heuristics (n.)

"serving to discover or find out," 1821, irregular formation from Greek heuriskein "to find; find out, discover; devise, invent; get, gain, procure" (from PIE *were- (2) "to find;" cognate with Old Irish fuar "I have found") + -istic. As a noun, from 1860. Greek had heuretikos "inventive," also heurema "an invention, a discovery; that which is found unexpectedly."

in the names of sciences or disciplines (acoustics, aerobics, economics, etc.), a 16c. revival of the classical custom of using the neuter plural of adjectives with Greek -ikos "pertaining to" (see -ic) to mean "matters relevant to" and also as the titles of treatises about them. Subject matters that acquired their English names before c. 1500, however, tend to be singular in form (arithmetic, logic, magic, music, rhetoric). The grammatical number of words in -ics (mathematics is/mathematics are) is a confused question.