回想 (かいそう) literally means “spin thoughts around,” or something like that. 想い (おもい) is, I believe, the direct object of 回す (まわす). Why are they not in the Japanese order (DOをVする)? I think it’s because the compound is Chinese in origin and therefore uses the same grammatical order as English (Subject Verb Object).
A less literal translation gives you “recall, recollect.” The other possibility is “flashback,” which is how I saw it used the other day. Pretty cool stuff.