To make a guess or conjecture about something.

अनुमान लगाना

English Usage: Can you guess the answer to this riddle?

Hindi Usage: क्या आप इस पहेली का उत्तर अनुमान लगा सकते हैं?

A guess is an estimation or supposition made without sufficient information.

अनुमान

English Usage: My guess is that it will rain tomorrow.

Hindi Usage: मेरा अनुमान है कि कल बारिश होगी।