because

American  

[bih-kawz, -koz, -kuhz] / bɪˈkɔz, -ˈkɒz, -ˈkʌz /

conjunction

1. for the reason that; due to the fact that.

   The boy was absent because he was ill.

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preposition

1. 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

1. because of, by reason of; due to.

   Schools were closed because of heavy snowfall.

because British  

/ -ˈkəz, bɪˈkɒz /

conjunction

1. (subordinating) on account of the fact that; on account of being; since

   because it's so cold we'll go home

2. (preposition) on account of

   I lost my job because of her

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Usage

See reason.

Etymology

Origin of because

First recorded in 1275–1325; Middle English bi cause; see by ( def. ), cause ( def. )

Example Sentences

"You don't want your measurement to strongly perturb the material you're studying because it can become harder to tell whether you're seeing the material's natural behavior or behavior caused by the experiment," Marino says.

From Science Daily • Jun. 23, 2026

The by-election was a petri dish that Labour had been watching closely, because if Burnham could beat Reform on that stage, it might signal that he could beat Reform in a general election.

From Slate • Jun. 23, 2026

Nevertheless, he finished top of the Fifa rankings for the game because of the continued attacking threat he posed.

From BBC • Jun. 23, 2026

Blackouts struck Milan and Turin because of the spike in the use of air conditioning.

From Barron's • Jun. 23, 2026

I know it’s ridiculous, because first of all, they won’t believe me.

From "Split the Sky" by Marie Arnold