noun / verb
surmise
ser-MYZE/sərˈmaɪz/
A guess based on incomplete evidence, or to make such a guess.
She studies the wet footprints and umbrella to surmise what happened.

Etymology
“Put upon” underlies the older meaning “accuse,” or lay a charge upon someone. The noun shifted from an allegation to a thought lacking certain evidence, giving the verb its modern sense of guessing.
In context
The mystery of this non-interference is unexplained and I can only surmise that a few tired troops had got left behind
More examples
- His explanation was only a surmise.
- We can surmise what happened, but the evidence is incomplete.
- The detective’s surmise proved correct.
Forms
surmise · surmises · surmised · surmising
Similar words
- conjecture
- Conjecture is an inference without firm proof; surmise often suggests a tentative conclusion from a few clues.
- suppose
- Suppose accepts or proposes a possibility; surmise particularly infers it from incomplete evidence.