Squirt means to shoot out liquid in a thin, quick stream. When you squeeze a water bottle hard, water squirts out of the opening. A lemon squirts juice when you squeeze it. Water guns work by squirting streams of water at targets (or friends on a hot day).

The word captures that sudden, forceful quality of liquid shooting out under pressure. A garden hose squirts water when you put your thumb over part of the opening. A ketchup bottle squirts when you squeeze it too hard. Sometimes squirting happens by accident, like when you bite into a juicy orange and juice squirts across the table.

As a noun, a squirt is the stream of liquid itself: “That was quite a squirt of mustard!” People also use squirt as a playful, slightly teasing nickname for a small or younger person, like calling a little brother “squirt.” This usage can sound friendly, but it can also feel annoying to the person being called it, since nobody likes being reminded they're smaller or younger.