because

conjunction

1. for the reason that; due to the fact that: The boy was absent because he was ill.

preposition

2. 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!

Idioms

3. because of, by reason of; due to: Schools were closed because of heavy snowfall.

conjunction

1. (subordinating) on account of the fact that; on account of being; sincebecause it’s so cold we’ll go home
2. because of (preposition) on account ofI 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.