Green’s Dictionary of Slang

a glance, esp. a leer.

1676		Etherege Man of Mode III i: I abominate the dull diversions there, the formal bows, the affected smiles, the silly by-words, and amorous tweers.
c.1707		‘Good Neighbour, Why Do You Look Awry’ in Farmer Merry Songs and Ballads (1897) IV 169: You wash, you lick, you smug, you trick, / You toss a twire a grin; / You nod and wink, and in his Drink, / You strive to draw him in.
1719		in D’Urfey Pills to Purge Melancholy V 74: You wash, you lick you smug, you trick, / You toss a twire a grin.