Because

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.
conjunction
(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
conj.

c.1300, bi cause “by cause,” modeled on French par cause. Originally a phrase, often followed by a subordinate clause introduced by that or why. One word from c.1400. As an adverb from late 14c. Clipped form cause attested in writing by mid-15c.