adverb
(interrogative) At what time? At which time? Upon which occasion or circumstance? Used to introduce direct or indirect questions about time.
At an earlier time and under different, usually less favorable, circumstances.
(relative) At which, on which, during which: often omitted or replaced with that.
(fused relative) The time at, on or during which.
(informal, in definitions or explanations) A circumstance or situation in which.
conjunction
At (or as soon as) that time that; at the (or any and every) time that; if.
During the time that; at the time of the action of the following clause or participle phrase.
At what time; at which time.
Since; given the fact that; considering that.
Whereas; although; at the same time as; in spite of the fact that.
pronoun
(interrogative) What time; which time.
noun
The time at which something happens.
interjection
(often humorous) That's enough: a command asking someone to stop adding something, especially an ingredient or portion of food or drink; used in, or as if in, literal response to 'Say when'.
(obsolete) Expressing impatience.