The quadrate bone.
A plane surface with four equal sides and four right angles; a square; hence, figuratively, anything having the outline of a square.
An aspect of the heavenly bodies in which they are distant from each other 90°, or the quarter of a circle; quartile.
Having four equal sides, the opposite sides parallel, and four right angles; square.
Produced by multiplying a number by itself; square.
Something that is four times the usual number, amount, size, etc.
A figure-skating jump with four revolutions in the air.
Being four times as long, as big or as many of something.
To multiply by four.
To increase by a factor of four.
To provide four parallel running lines on a given stretch of railway.