for the reason that; due to the fact that: The boy was absent because he was ill.
Informal. (used directly before a noun, adjective, verb, interjection, etc., to convey a very concise rationale, excuse, or explanation): We’re a little like monkeys because evolution. He doesn’t practice enough: because lazy. I love doughnuts because yum!
because of, by reason of; due to: Schools were closed because of heavy snowfall.
(subordinating) on account of the fact that; on account of being; since: because it's so cold we'll go home
(preposition) because of, on account of: I lost my job because of her