an estimate based on little or no information
"She was just guessing how much paint we would need since she didn't know the exact dimensions of the room."
The act of making a guess; estimate or prediction; foresight.
"Based on her track record, my boss is more interested in accurate guessing than rigid planning when forecasting next quarter's sales."
present participle of guess
"She is guessing that he will arrive late, so she has already started dinner without him."