late 14c., "learned, skilled in learning;" c. 1500 as "related or belonging to philosophy or philosophers;" see philosophy + -ical. Related: Philosophically.

Old English cuðe, past tense of cunnan "to be able" (see can (v.1)); ending changed 14c. to standard English -d(e). The unetymological -l- was added 15c.-16c. on model of would, should, where it is historical. Could be as a response to a suggestion, indicating it may be correct, is by 1938.

"one skilled or learned in mathematics," early 15c., mathematicion, from Old French mathematicien, from mathematique, from Latin mathematicus "of or belonging to mathematics," from Latin mathematica (see mathematic).

also auto-immune, "arising from an abnormal immune response to a normal body part," 1952, from auto- + immune. Related: Autoimmunity, attested by 1903 as "immunity, natural or acquired, effected by the unaided powers of the organism, independent of external agencies." Modern sense of "immune responses of an organism against its own healthy cells and tissues" is from 1950s.

mid-12c., crafti, "skillful, clever, learned," from Old English cræftig "strong, powerful," later "skillful, ingenious," acquiring after c. 1200 a bad sense of "cunning, sly, skillful in scheming," the main modern sense (but through 15c. also "skillfully done or made; intelligent, learned; artful, scientific"); see craft (n.) + -y (2). Perhaps to retain a distinctly positive sense, Middle English also used craftious as "skillful, artistic" (mid-15c.). Related: Craftily; craftiness.

late 15c., "to distribute into groups or classes," from Old French assorter "to assort, match" (15c., Modern French assortir), from a- "to" (see ad-) + sorte "kind, category," from Latin sortem (nominative sors) "lot; fate, destiny; share, portion; rank, category; sex, class, oracular response, prophecy" (from PIE root *ser- (2) "to line up"). Related: Assorted; assorting.