"and not," mid-13c., from ne (adv.) "no" + or (conj.), or else a contraction of Middle English nauther (see neither) and influenced in form by or. Generally correlative to neither or some other negative.

"negation; in the negative; the arguments, arguers, or voters against a proposal" (mainly in pro and con), 1570s, short for Latin contra "against" (see contra (prep., adv.)). Compare pro (n.2).

"deny, make negative or null," 1795 (with an isolated use from 1620s), a back-formation from negation, or else from Latin negatus, past participle of negare, from PIE root *ne- "not." Related: Negated; negates; negating.

1846, "characteristic ideas or methods of professional persons," from professional (adj.) + -ism. In late 19c., in sports and amusements, sometimes with a negative sense, implying pursuit of some activity so marked as to be objectionable or offensive (1879).

"teetotaler, one who practices or advocates total abstinence from intoxicating drink," 1860, from Late Greek nēphalismos, from nēphalios "sober," from nēphein "be sober," often metaphorical, from IE *(n)egwh-"sober," with negative particle + *hegwh- "drink." Related: Nephalism (1859).

Old English neodian "be necessary, be required (for some purpose)," intransitive; also transitive, "require, have need of," from the same root as need (n.). Meaning "to be under obligation (to do something)," especially in negative or interrogative sentences implying obligation or necessity, is from late 14c. Related: Needed; needing. The adjectival phrase need-to-know is attested from 1952. Dismissive phrase who needs it?, popular from c. 1960, is a translated Yiddishism.

Need, especially in negative and interrogative sentences implying obligation or necessity, is often used, in the present, before an infinitive, usually without to, need being then invariable (without the personal terminations of the second and third persons singular): as, he or they need not go; need he do it? [Century Dictionary]