From Longman Dictionary of Contemporary EnglishI guessI guessspoken a) used to say that you think something is true or likely, although you are not sure His light’s on, so I guess he’s still up. b) used to say that you will do something even though you do not really want to I’m tired, so I guess I’ll stay home tonight. → guess
Examples from the CorpusI guess• Slim was gone-to Montana, I guess.• Well fifteen, half an hour and then a break, I guess.• You could add something about the hurricane, I guess.• Rob just got tired of living with her, I guess.• They live somewhere between Saginaw and Lansing, I guess.• I did not know the name, but I guessed at once who she was.• His light's on, so I guess he's still up.• I guess his dad had to work two jobs when they were little.• I guess how each one I guess.• I guess I'll stay home tonight.• From the shape of its lights I guessed it was one of the small Peugeots.• "Is the truck safe to drive now?" "I guess so."• I guess this is the best way to do it.• I am weary. I guess you read one porno magazine and the second one is just the same.