to try and give an answer or make a judgement about something without being sure of all the facts

to find the right answer to a question or the truth without knowing all the facts

She guessed the answer straight away.

You'll never guess what she told me.

You would never guess (that) she had problems. She’s always so cheerful.

So it was Rob who broke the window? I might have guessed!

If I had to guess, I'd say she was the one responsible for this.

used to show that you are going to say something surprising or exciting

to suppose that something is true or likely

I guess (that) you’ll be looking for a new job now.

‘Are you ready to go?’ ‘Yeah, I guess so.’

‘They aren't coming, then?’ ‘I guess not.’

an attempt to give an answer or an opinion when you cannot be certain if you are right

LEARNit Dictionary