Entries linking to straighten
Meaning "true, direct, honest" is from 1520s. Of communication, "clear, unambiguous," from 1862. Sense of "undiluted, uncompromising" (as in straight whiskey, 1874) is American English, first recorded 1856. As an adverb from c. 1300, "in a straight line, without swerving or deviating." Theatrical sense of "serious" (as opposed to popular or comic) is attested from 1895; vaudeville slang straight man first attested 1923.
Go straight in the underworld slang sense is from 1919; straighten up "become respectable" is from 1907. To play it straight is from 1906 in theater, 1907 in sports ("play fair"), with figurative extension; later perhaps also from jazz. Straight arrow "decent, conventional person" is 1969, from archetypal Native American brave name. Straight shooter is from 1928. Straight As "top grades" is from 1920.
word-forming element making verbs (such as darken, weaken) from adjectives or nouns, from Old English -nian, from Proto-Germanic *-inojan (also source of Old Norse -na), from PIE adjectival suffix *-no-. Most active in Middle English and early modern English, hence most verbs in -en are comparatively recent.
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The students straightened when the teacher entered