Stipulate

google

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early 17th century: from Latin stipulat- ‘demanded as a formal promise’, from the verb stipulari .

wiktionary

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From Latin stipulātus, perfect active participle of stipulor(“I demand a guarantee”).

stipule +‎  -ate

etymonline

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stipulate (v.)

1620s, "bargain, make a contract" (intransitive), back-formation from stipulation, or else from Latin stipulatus, past participle of stipulari "exact (a promise), bargain for." Transitive sense of "demand as a condition" is from 1640s. Related: Stipulated; stipulating.