Etymology: Middle English streght, straight, from past participle of strecchen to stretch — more at stretch
Date: 14th century
a. free from curves, bends, angles, or irregularities <straight hair> <straight timber> b. generated by a point moving continuously in the same direction and expressed by a linear equation <a straight line> <the straight segment of a curve> 2. a. lying along or holding to a direct or proper course or method <a straight thinker> b. candid, frank <a straight answer> c. coming directly from a trustworthy source <a straight tip on the horses> d. (1) having the elements in an order <the straight sequence of events> (2) consecutive <12 straight days> e. having the cylinders arranged in a single straight line <a straight 8-cylinder engine> f. plumb, vertical <the picture isn't quite straight> 3. a. exhibiting honesty and fairness <straight dealing> b. properly ordered or arranged <set the kitchen straight> <set us straight on that issue>; also correct <get the facts straight> c. free from extraneous matter ; unmixed <straight whiskey> d. marked by no exceptions or deviations in support of a principle or party <votes a straight Democratic ticket> e. having a fixed price for each regardless of the number sold f. not deviating from an indicated pattern <writes straight humor> <a straight-A student> g. (1) exhibiting no deviation from what is established or accepted as usual, normal, or proper ; conventional; also square 5f (2) not using or under the influence of drugs or alcohol h. heterosexual 4. being the only form of remuneration <on straight commission> • straightish adjective • straightly adverb • straightness noun II. adverb Date: 14th century in a straight manner <came straight home from work> III. transitive verb Date: 15th century chiefly Scottish straighten IV. noun Date: 1645 1. something that is straight: as a. a straight line or arrangement b. straightaway; especially homestretch c. a true or honest report or course 2. a. a sequence (as of shots, strokes, or moves) resulting in a perfect score in a game or contest b. first place at the finish of a horse race ; win 3. a poker hand containing five cards in sequence but not of the same suit — see poker illustration 4. a person who adheres to conventional attitudes and mores
New Collegiate Dictionary. 2001.