Etymology
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suppose (v.)
early 14c., "to assume as the basis of argument," from Old French suposer "to assume" (13c.), probably a replacement (influenced by Old French poser "put, place") of *suppondre, from Latin supponere "put or place under; to subordinate, make subject," from assimilated form of sub "under" (see sub-) + ponere "put, place" (past participle positus; see position (n.)). Meaning "to admit as possible, to believe to be true" is from 1520s.
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supposititious (adj.)
"put by artifice in place of another," 1610s, from Latin supposititius, from suppositus, past participle of supponere (see suppose).
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supposably (adv.)
"as may be supposed," 1795, not originally American English, alteration of supposedly, or else from supposable (1680s), from suppose (v.) + -able.
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supposed (adj.)
"believed or thought to exist," 1580s, past-participle adjective from suppose (v.); often with the -e- pronounced, to distinguish it from the passive past tense supposed, now common in the sense of "to have a duty or obligation" (1859).
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suppository (n.)
late 14c., from Medieval Latin suppositorium "a suppository," noun use of neuter of Late Latin adjective suppositorius "placed underneath or up," from Latin suppositus, past participle of supponere "put or place under" (see suppose).
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presuppose (v.)

early 15c., altered from presupponen (c. 1400), "assume beforehand or in the beginning," from Old French presupposer (14c.), formed in French or else from Medieval Latin praesupponere; see pre- + suppose. The meaning "take for granted in advance of actual knowledge or experience" is from 1520s. Related: Presupposed; presupposing.

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supposition (n.)
early 15c., a term in logic, "assumption, hypothesis," from Medieval Latin suppositionem (nominative suppositio) "assumption, hypothesis, a supposition," noun of action from past participle stem of supponere (see suppose); influenced by Greek hypothesis. In classical Latin, "a putting under, substitution." Earlier in English in the same sense was supposal (late 14c.). Related: Suppositional; suppositionally.
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presupposition (n.)

1530s, "surmise, conjecture, supposition antecedent to knowledge," from French présupposition and directly from Medieval Latin praesuppositionem (nominative praesuppositio), noun of action from past-participle stem of Latin praesupponere, from prae "before" (see pre-) + suppositio (see suppose). Meaning "postulation as of an antecedent condition," hence "a prerequisite" is from 1570s.

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*upo 

Proto-Indo-European root meaning "under," also "up from under," hence "over."

It forms all or part of: above; assume; Aufklarung; eave; eavesdropper; hyphen; hypo-; hypochondria; hypocrisy; hypotenuse; hypothalamus; hypothesis; hypsi-; hypso-; opal; open; oft; often; resuscitate; somber; souffle; source; soutane; souvenir; sub-; subject; sublime; subpoena; substance; subterfuge; subtle; suburb; succeed; succinct; succor; succubus; succumb; sudden; suffer; sufficient; suffix; suffrage; suggestion; summon; supine; supple; supply; support; suppose; surge; suspect; suspend; sustain; up; up-; Upanishad; uproar; valet; varlet; vassal.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit upa "near, under, up to, on," Greek hypo "under," Latin sub "under, below," Gothic iup, Old Norse, Old English upp "up, upward," Hittite up-zi "rises."

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cred (n.)

slang shortening, I suppose, of credit, credibility or credentials; by 1992.

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