etymologeek.com dictionary
English word because comes from Middle English by (Be.), Middle English cause (Cause.).

Because etymology history?

Because detailed word origin explanation

Dictionary entryLanguageDefinition
by Middle English (enm) Be.
cause Middle English (enm) Cause.
bi cause Middle English (enm)
because English (eng) (uncommon, slang, especially, Internet) On account of, because of. [since at least the 20th century] (obsolete) So that, in order that. [15th-17th c.]. As is known, inferred, or determined from the fact that.. By or for the cause that; on this account that; for the reason that. (archaic) For the reason (that).. On account (of), for sake (of).. Used alone to refuse to provide a full answer a [...]

Words with the same origin as because

Descendants of cause
cuz