ShakespearesWords.com

square, by the

Old form(s): squier, squire

accurately, exactly, with great precision

LLL V.ii.474	[Berowne to Boyet, of the Princess] Do not you know my lady's foot by the square
WT IV.iv.336	[Servant to Shepherd, of the trios of performers] not the worst of the three but jumps twelve foot and a half by th'square [F squire]