Definition of “square” - Learner’s Dictionary

square

noun [ C ] uk us /skweər/
SHAPE

A2 a shape with four equal sides and four 90° angles

PLACE

A2 an open area with buildings around it, often in the centre of a town:

Trafalgar Square
NUMBER

a number that results from multiplying a number by itself:

The square of 3 is 9.

(Definition of “square noun” from the Cambridge Learner's Dictionary © Cambridge University Press)