Directly, firmly, or exactly in a particular position or manner; honestly and straightforwardly.
From 'square' plus '-ly' suffix. 'Square' derives from Old French 'esquarre' (carpenter's square), and the adverb developed senses of 'directly' and 'honestly' from the geometric precision and fairness associated with right angles.
The connection between geometric squares and moral honesty runs deep in language - we talk about 'square deals' and 'squaring with someone.' This reflects how mathematical precision became a metaphor for ethical behavior, suggesting that moral truth, like geometry, should be exact and unambiguous.
Complete word intelligence in one call. Free tier — 50 lookups/day.