As a noun from early 15c., "that which affirms or asserts." American English affirmative action "positive or corrective effort by employers to prevent discrimination in hiring or promotion" is attested from 1935 with regard to labor unions (reinstatement of fired members, etc.). The specific racial sense is attested from 1961; by late 1970s the sense had shifted toward pro-active methods such as hiring quotas. Related: Affirmatively.
inarticulate sound, attested from c. 1600; uh-huh, spoken affirmative (often ironic or non-committal) is recorded by 1894; negative uh-uh is attested from 1924.
mid-15c., "clarifying, explanatory," from Medieval Latin declaratorius, from Latin declarator, from declarare "make clear, reveal, disclose, announce," from de-, here perhaps an intensive prefix (see de-) + clarare "to clarify," from clarus "clear" (see clear (adj.)). From 1580s as "making declaration or exhibition, affirmative." Related: Declaratorily.
c. 1500, of horns, ultimately imitative, also found in Middle Low German and Low German tuten "blow a horn." Related: Tooted; tooting. Tooting as a strong affirmative (as in you're damned tootin') is attested from 1932, American English. Reduplicated form rootin' tootin' "noisy, rambunctious" is recorded by 1924.
1731, "pronounce with an accent," from Medieval Latin accentuatus, past participle of accentuare "to accent," from Latin accentus "song added to speech," from ad "to" (see ad-) + cantus "a singing," past participle of canere "to sing" (from PIE root *kan- "to sing"). Figurative meaning "emphasize, place an accent or emphasis on" is recorded from 1865.
You've got to accentuate the positive
Eliminate the negative
Latch on to the affirmative
Don't mess with Mister In-Between
["Ac-Cent-Tchu-Ate the Positive," 1944, music by Harold Arlen, lyrics by Johnny Mercer]
Related: Accentuated; accentuating.
c. 1400, negatif, "expressing denial" (a sense now rare or obsolete), from Anglo-French negatif (early 14c.), Old French negatif (13c.) and directly from Latin negativus "that which denies," from negat-, past-participle stem of negare "deny, say no" (see deny).
The meaning "expressing negation" is from c. 1500; that of "characterized by absence of that which is affirmative or positive" is from 1560s. Algebraic sense, denoting quantities which are a subtraction from zero, is from 1670s. The electricity sense is from 1755.
Negative Capability, that is when a man is capable of being in uncertainties, Mysteries, doubts without any irritable reaching after fact and reason. [John Keats, letter, Dec. 21, 1817]
1670s, "belief in a deity or deities," (as opposed to atheism); by 1711 as "belief in one god" (as opposed to polytheism); by 1714 as "belief in the existence of God as creator and ruler of the universe" (as opposed to deism), the usual modern sense; see theist + -ism.
Theism assumes a living relation of God to his creatures, but does not define it. It differs from deism in that the latter is negative and involves a denial of revelation, while the former is affirmative, and underlies Christianity. One may be a theist and not be a Christian, but he cannot be a Christian and not be a theist. [Century Dictionary]