RhymeZone: because definitions

Definitions of because:

adverb: (archaic) For the reason (that).
adverb: On account (of), for sake (of).
adverb: (by ellipsis) Used alone to refuse to provide a full answer a question begun with "why", usually taken as an anapodoton of the elided full phrase "Because I said so".

(Definitions from Wiktionary)