The story
A cucumber is mostly water, and its crisp flesh feels cool to the touch even on a warm day. That plain kitchen fact gave English one of its longest-lasting pictures of calm.
The first known printing is in John Gay’s 1732 poem “New Song on New Similes,” a playful piece packed with comparisons. One line runs: “Cool as a cucumber could see / The rest of womankind.”
Gay was having fun stacking similes, and not all of them lasted. Some, like “pert as a pear-monger,” faded along with the street sellers of pears they described. The cucumber stayed.
The “cool” in the phrase is about temper, not temperature. It describes someone who stays unbothered while everything around them heats up.
Nearly three centuries on, the phrase is as fresh as ever, and it has outlasted many of the comparisons in Gay’s poem.
