There are multiple meanings for straight-
1. Traditional meaning: Without a bend or curve, evenly formed or set, not
crooked.
2. Traditional meaning: Figurative; a) frank, honest, upright, b) right, correct
3. Traditional meaning: in
proper order (numeric, chronologic, alphabetic, etc...),
4. Traditional meaning: without interruption or
break; continuous, in an unbroken series, without reservations or exceptions,
5. Traditional meaning: unmixed, undiluted (reference to
alcohol, or other substances, without qualification, unmodified,
6. Traditional meaning: showing no emotion or humor, serious rather than comic, natural rather than eccentric,
7. Traditional meaning: reliable, sure, authoritative,
8. Traditional meaning: behaving in a conventional manner, holding orthodox views, conventional, standard,
normal,
9. Traditional meaning: made up of a set of five cards, as in
poker,
10. Slang: term used in agreement, approval,
11. Slang: term used to qualify one's sexual preference,
12. Slang: term used to denote the validity of a statement or claim,
13. Slang: term used to describe a manner of frank communication, i.e.- straight talk,
14. Slang: term used to determine level of understanding, agreement, or otherwise mutual understanding and agreement