Past
Part of speech: adverb
Definition: in a direction that passes
Part of speech: preposition
Definition: beyond in place, quantity or time
Part of speech: noun
Definition: The period of time that has already happened, in contrast to the present and the future. The past tense.
Part of speech: adjective
Definition: Having already happened; in the past; finished. Relating to the past. (of a period of time) the one before this one
Example sentence: The past cannot be changed. The future is yet in your power.
Historic
Part of speech: adjective
Definition: having importance or significance in historybelonging to the past; historical (see note below)
Example sentence: There are historic situations in which refusal to defend the inheritance of a civilization, however imperfect, against tyranny and aggression may result in consequences even worse than war.