You can see the full category hierarchy on the Category Map.

Loose apronyms:
Perfect Apronyms OnlyAll Apronyms
A AND A EQUALS BAlphabetic Algebra Never Dies. Appealling Equations Quite Useful, Although Lacking Spelling Beauty. Tony McCoy O'Grady
ABACUSAbundant Beads, Addition & Calculation Utility System. Tony McCoy O'Grady
ABACUS (2)All Beads Are Calculated Using Slides Rico Leffanta
ADDITIONArithmetic Device Drummed Into Tots... It's Only Natural. Angela Brett
ALGEBRA (2)Abstract Logic Governs Everything - Broad-Ranging Applications. Angela Brett
ALGEBRA (4)Arithmetic Logically Grasps, Expressing Bounties: Representation Algebraic! Charles H. Montgomery, Jr.
ALGEBRA (5)Abstract Logic Generalises Everything; Beautiful Relationships Appear Angela Brett
ALGEBRA (6)Arithmetic Lovingly Grasps, Expressing Bounties: Representation Algebraic! Charles H. Montgomery, Jr.
ALGEBRA (7)Arithmetic Literally Generalized! Expressions Birth Real Abstraction/Adaptibility! Charles H. Montgomery, Jr.
ARITHMETICA Really Irritating Task Humans Must Endure 'Til It Calculates. Timothy Chambers
ARITHMETIC (3)Adding Real Integers Together Has Made Everyone Think It's Complicated Angela Brett, when somebody mentioned the mnemonic 'A Red Indian Thought He Might Eat Toffee In Church', and noted that a politically correct version would spell anathematic.
CALCULATORComplex And Liberating Creation - Users Lose Ability To Orchestrate Ratios Tony McCoy O'Grady
CALCULATOR (2)Challenged - Arithmetically Love Computing Using Least-Advanced, Typically Onmoney Reckoning! Charles H. Montgomery, Jr.
CALCULATOR (3)Children Always Love Computing Using Least-Advanced, Typically Onmoney Reckoning! Charles H. Montgomery, Jr.
CALCULATOR (4)Children Always Look Comfortable Using Least-Advanced, Typically Onmoney Reckoning! Charles H. Montgomery, Jr.
CHAOSCreated Havoc Amongst Orthodox Scientists Angela Brett
CHAOTICCan't Highly Accurately Observe These Iterative Creations. Angela Brett, after reading about the mathematical phenomenon chaos... it's all about sequences which seem totally random but are generated by a simple mathematical rule - however, slight changes in the starting values can drastically change the whole thing, so chaotic motion is still very difficult to predict.
CODE (2)Confusingly Ordered Diatribe, Enigma Gavin Lambert
DECIMAL POINTDot Emphasising Change In Magnitude... Any Leftward Part's Obviously Integral, Nearby's Tenths. Angela Brett
DETERMATHATIONSDaily Explain/Energise/Engineer! Test/ Extend Reality! Multiply Algorithms / Tools Habile! Advance/Adapt! Transfinites: Infinities/Increasing/Infinitely, Observe Nuances! Sciences/Study! Charles H. Montgomery, Jr.
Words & Wordplay:Made Up Words
EIGENVECTORExcess Instructions Generate Exhausting, Not-Very-Exciting Classes. Tedium Often Results. Angela Brett, while sitting through a lecture about eigenvalues and eigenvectors (a topic which everyone in the class had learnt about at least once) which was being taught agonisingly slowly.
Education:Slow Teaching
ENCRYPTIONEach New Code Requires Your Powers To Interpret Others' Notes. Angela Brett
HAM SANDWICH THEOREMHere's A Mathematical Statement Anyone (Not Dealing With Integrals) Can Hungrily Test. Halve Exactly Outer Rolls, Even Meat. Angela Brett (From the Collins dictionary of Mathematics: ham sandwich theorem, n, a colourful name for the theorem that given three volumes in Euclidean three-space, there is at least one plane which simultaneously bisects the three volumes. As a consequence, any sandwich may be cut in such a way that the two pieces have equal amounts of filling and equal amounts of each slice of bread.)
Food & Drink
INFINITYIncrement Numbers Forever - It's Nuts, I Tell You! Angela Brett
INTEGRATION PROJECTIt's Not Too Easy Getting Result... Adding That Infinity Of Negligible Parts. Relying On Just Exhaustive Calculation's Terrible! Angela Brett, when somebody searched for that phrase on the Acronyms website.
MATHMuch About Tedious Hypotheses PiMaster
MATH (2)Manna! Abstract/Apparent Truth Habitually/Healthfully! Charles H. Montgomery, Jr.
MATHEMATICSMethodology Attempting To Harmonise Equations, Many Apply Techniques In Calculus & Statistics. Angela Brett
MATHEMATICS (3)Meet Absolute Truth Here... Employ Minimal Assumptions To Imply Complicated Statements. Angela Brett
MATHSModels, Axioms, Theorems, Hypothetical Structures Angela Brett
MATH THEM MATICS!Multiply Access To Help! Training ==> Housing, Employment, Meals! Mobilise Addicts Thru Innovative Compassion! Soar! Charles H. Montgomery, Jr.
MATH THEM MAT TICSMotivate All Tots Humanely! Technical Humans Elevate Man! Math Advances Technology! Technologists: Invent Comforts Social! Charles H. Montgomery, Jr.
MATH WHIZ!Math's Acme, Traveling Higher! Wishes He'd Invented Zero! Charles H. Montgomery, Jr. Relaxing from TEDIOUS APRONYMISING! (after CIRCLE PERIMETER)
MATH WIZMultiplications & Additions - This 'Hard Work' Is Zero Tony McCoy O'Grady
ODDEST (2)Often Directly Divisible, Excepting (Surely) Twos TMcCO'G
PLUSPositively Lonely Unary's Superfluous Angela Brett, as it is not usually necessary to indicate that a number is positive with a plus sign.
POLARPosition's Obvious... Length, Angle Required. Angela Brett, referring to polar coordinates.
PRIMEProduce Right Integers Multiplying Eternity Charles H. Montgomery, Jr.
PRIME POWERFUL NUMBERS!Positive = Recursively Invoke (Multiplication * {Each Prime, One Withheld!} ^ Exponent). Represent Factorisation Uniquely, Luminescing Naturals Unlimited! "Mathematics By Expansion: Reduces Swiftly!" Charles H. Montgomery, Jr. In apronym, PRIME is a transitive verb. One Withheld! means that mathematicians do not define ONE as a PRIME, even though PRIME commonly means FIRST. ONE is called a UNIT. "Mathematics By Expansion: Reduces Swiftly!" fractions. Fundamental Theorem of Arithmetic n. Every natural number is either prime or may be decomposed uniquely into prime factors.
PRIMESPositively Represent Individuals! Multiply Essential Services! Charles H. Montgomery, Jr.
PRIMES (2)Positives: Represented Integers. Multiplications Essentially Singular! Charles H. Montgomery, Jr.
RABATRotate And Bring About Togetherness Tony McCoy O'Grady
ROOTRadical, Or Originating Thing Tony McCoy O'Grady
Assorted Nouns
SEQUENCESome Expect Quite Unremarkable Ending - Numbers Converging Evenly. Angela Brett
SEQUENCE (2)Sometimes Especially Queer Unruly Entity Named Chaos Emerges. Angela Brett
SINESide Is Numerically Expressed Tony McCoy O'Grady
SINE (2)Symmetry Is Not Even Angela Brett
SLOPESlanted Lines Offer Plainest Equations Angela Brett
SLOPE (2)Straight Lines Observed? Proportional Elements. Angela Brett
THIRTY = FRIENDS!Thirty (Halves {Initial = Remotest - Two} Year) = Four (Regeneration Increases!) + Eleven + Nine Down + Six! Charles H. Montgomery, Jr. Sum 30-Day Month Numbers: 4(April)+6(June)+9(September)+11(November)=10+20=30 (!) One of my original discoveries when I was less than 45. (Halves {Initial = Remotest - Two} Year): First Half of Year ==>(Initial=4) = (Remotest=6) - 2. Last Half of Year ==>(Initial=9) = (Remotest=11) - 2."Four (Regeneration Increases!) Spring starts late in Three (21 March 2003 in N. Hemisphere)." "Nine\Down\ Down!=Fall! in September."
TABLESTruth Arrays... Boolean Logic Explicitly Stated Angela Brett, referring to truth tables.
ZIP (3)Zero Incrementation Power Charles H. Montgomery, Jr.