Definitions:
extending or moving uniformly in one direction only; without a curve or bend

properly positioned so as to be level, upright, or symmetrical

not evasive; honest

in continuous succession

(of an alcoholic drink) undiluted; neat

(of a person) heterosexual

(of a person) conventional or respectable

in a straight line; directly

in or into a level, even, or upright position

correctly; clearly

without a break; continuously

a part of something that is not curved or bent, especially a straight section of a racecourse

a heterosexual person.

a conventional or respectable person.

(in poker) a continuous sequence of five cards.

(in township slang) a 750 ml bottle of alcoholic drink.