guess; expectation; anticipation
Used when one has a rough idea or expectation about something, often based on intuition or prior knowledge. Common in phrases like 心当てがある (to have an idea/guess).
Do you have any guess who the culprit is?
彼が来るという心当てはなかった。
I had no expectation that he would come.
Compound of 心 (こころ, heart/mind) and 当て (あて, guess/aim). The exact historical derivation is uncertain, but the word literally suggests 'aiming with the mind'.