sophomoric adj.

1680s, "student in the second year of university study," literally "arguer," altered from sophumer (1650s), from sophume, an archaic variant form of sophism, ultimately from Greek sophistēs "a master of one's craft; a wise or prudent man, one clever in matters of daily life."

The modern form probably is by folk etymology derivation from Greek sophos "wise" + mōros "foolish, dull" (see moron), "as if in allusion to the exaggerated opinion which students at this age are apt to have of their wisdom" [Century Dictionary]. The 17c. -er is perhaps based on philosopher, sorcerer, sophister, etc.

The original reference of the "arguer" name might be to the dialectic exercises that formed a large part of education in the middle years. At Oxford and Cambridge, a sophister (from sophist with spurious -er as in philosopher) was a second- or third-year student (what American colleges since mid-18c. would call a junior might be a senior sophister).

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.