Big gulp

SWIG

A quick drink often taken from a bottle or glass.

"Big gulp" is a playful way to describe taking a large drink, which is commonly called a "swig." The clue hints at the action of drinking in a casual, exaggerated way, leading to the short and snappy answer "SWIG." It’s a straightforward example of how crossword clues often use everyday phrases to point to simple, familiar words.