WordWeb Online

1. Find the solution to (a problem or question) or understand the meaning of
   - solve, work out, figure out, puzzle out, lick [N. Amer, informal], work, suss [Brit, informal], unriddle
    
2. Examine so as to determine accuracy, quality, or condition
   "suss out the brakes";
   - check, check up on, look into, check out, check over, go over, check into, suss [Brit, informal], sus [Brit, informal]

Derived forms: sussed out, susses out, sussing out

Type of: analyse [Brit, Cdn], analyze [N. Amer], canvass, examine, study, understand