English word obtain comes from Old French optiner

Detailed word origin of obtain

Dictionary entry	Language	Definition
optiner	Old French (fro)
obtenir	Anglo-Norman (xno)
obtain	English (eng)	(intransitive) To exist or be the case; to hold true, be in force. [from 17th c.]. (intransitive, obsolete) To prevail, be victorious; to succeed. [15th–19th c.]. (intransitive, obsolete) To secure (that) a specific objective or state of affairs be reached. [15th–19th c.]. (transitive) To get hold of; to gain possession of, to procure; to acquire, in any way. [from 15th c.]. (transitive, [...]