Guess
Speculation
noun, する verb
A recollection and measurement of the situation is what I use to make a guess and speculation.
おくそく
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
人々は、その試合は八百長だったのではないかと憶測している。
People are speculating that the match may have been fixed.
これはただの憶測だけどね。
It's just my guess.
コウイチの引退について、憶測が飛び交っている。
There has been a lot of speculation about Koichi's retirement.