(US) That which is certain.

(from Kantian philosophy on) A thing as it is independent of any conceptualization or perception by the human mind, postulated by practical reason but existing in a condition which is in principle unknowable and unexperienceable.

(LGBT, slang) A conceited person, usually a woman or a gay man.

A close call, a close shave, a close thing

Something genuine and of high quality, as opposed to an inferior imitation.

Precedes the key point of an explanation.

(sequence) Used to introduce the first item in a possible sequence

(sequence) Used to introduce an additional item in a possible sequence

(informal) An action that yields undesirable results to its subject.

(chiefly UK) Something done habitually or according to social norms, expectations, etc.