noun, noun or participle which takes 'suru'
surmise; conjecture; speculation
Rare formal noun and suru-verb for forming a tentative judgment based on incomplete evidence. More common alternatives include 推測, 憶測, or 推察.
その結論はあくまで想察に過ぎない。
That conclusion is nothing more than conjecture.
彼は状況から想察して、そう判断した。
He judged so by surmising from the situation.