noun

• (geometry) A polygon with four straight sides of equal length and four right angles; an equilateral rectangle; a regular quadrilateral.
  "I took refuge in the square form and exhibited a picture which consisted of nothing more than a black square on a white field."
• Something characterized by a square, or nearly square, form.
• Something characterized by a square, or nearly square, form.
• An L- or T-shaped tool used to place objects or draw lines at right angles.

adj

• Forming a right angle (90°).
  "The foundation has to be level and the framing has to be square."
• Forming a right angle (90°).
• (slang, derogatory) Socially conventional; boring.
  "It was a square town, but that didn't bother me. I knew I didn't have to live a square life."
• (cricket) In line with the batsman's popping crease.

verb

• (transitive) To adjust so as to align with or place at a right angle to something else; in particular:
  "The casting was mounted on a milling machine so that its sides could be squared."
• (transitive) To adjust so as to align with or place at a right angle to something else; in particular:
  "to square the yards"
• (transitive) To adjust so as to align with or place at a right angle to something else; in particular:
• (ambitransitive) To resolve or reconcile; to suit or fit.
  "John can square this question up for us."