guess

fair, good, reasonable, safe

It's a safe guess that most people prefer coffee to tea in the morning.

calculated, educated, informed, inspired, intelligent

She made an informed guess about which job applicant would be the best fit for the team.

lucky

I had no idea what the answer was, but my lucky guess turned out to be correct.

have, hazard, make, take

I'll take a guess and say the meeting is probably next Tuesday afternoon.

give sb

I'll give you a guess about what's in the box, but you probably won't get it right.

at a ~

At a guess, she probably left the party early because she wasn't feeling well.

~ about/as to/at

I can only guess at what she meant when she gave that strange look.

incorrectly, wrong

I guessed incorrectly about the time of the meeting and arrived thirty minutes early.

never

I could never guess the right answer even after thinking about it for an hour.

can/could

I could guess what she was thinking from the expression on her face.

can only

Without more information about the accident, we can only guess what really happened.

be easy to, not be difficult to, not be hard to

It wasn't difficult to guess why she looked so upset after the meeting.

at

The children were guessing at how many sweets were in the jar.

from

I guessed from the smell of fresh bread that the bakery had just opened.

could/might/should have guessed

When she didn't answer her phone all day, I should have guessed she was angry with me.

let me guess

I haven't told you my birthday yet, but let me guess—you think I'm a Gemini.