guess

Etymology 1

From Middle English gessen, probably of North Germanic origin, from Old Danish getse, gitse, getsa (“to guess”), from Old Norse *getsa, *gitsa, from Proto-Germanic *gitisōną (“to guess”), from Proto-Germanic *getaną (“to get”), from Proto-Indo-European *gʰed- (“to take, seize”). Cognate with Danish gisse (“to guess”), Norwegian gissa, gjette (“to guess”), Swedish gissa (“to guess”), Saterland Frisian gisje (“to guess”), Dutch gissen (“to guess”), Low German gissen (“to guess”). Related also to Icelandic giska ("to guess"; from Proto-Germanic *gitiskōną). Compare also Russian гада́ть (gadátʹ, “to conjecture, guess, divine”), Albanian gjëzë (“riddle”) from gjej (“find, recover, obtain”). More at get.

verb

1. To reach a partly (or totally) unqualified conclusion.
2. To solve by a correct conjecture; to conjecture rightly.
   He who guesses the riddle shall have the ring.
3. (chiefly US) to suppose (introducing a proposition of uncertain plausibility).
   That album is quite hard to find, but I guess you could try ordering it online.
   "Are you a member of the union?" "Sure." "Then you'll get your job, I guess. Have you any friends?" 1914–1915, Arthur Conan Doyle, The Valley of Fear
4. (colloquial) To think, conclude, or decide (without a connotation of uncertainty). Usually in first person: "I guess".
   "I guess you were right." "What did he say?" "He guesses you were right."
   "I guess I'll go to bed."
5. (obsolete) To hit upon or reproduce by memory.

Etymology 2

From Middle English gesse. Cognate with Dutch gis (“a guess”).

noun

1. A prediction about the outcome of something, typically made without factual evidence or support.
   If you don't know the answer, take a guess.
   "But I shall have eleven guesses," answered Ozma. "Surely I ought to guess one object in eleven correctly; and, if I do, I shall rescue one of the royal family and be safe myself. Then the rest of you may attempt it, and soon we shall free all those who are enslaved." 1907, L. Frank Baum, Ozma of Oz
   We are twelve billion light years from the edge / That's a guess 2005, Mike Batt (lyrics and music), “Nine Million Bicycles”, performed by Katie Melua