a1400 (a1325) (Gött.) l. 13448 Es na foul sua gleg of ei.
a1449 W. Bower in (1759) II. 376 Wyth prik ȝoukand eeris, as the awsk gleg.
c1540 J. Bellenden in tr. H. Boece sig. Ciij Thir mussillis ar sa doyn gleg of twiche and heryng, that [etc.].
1808–80 J. Jamieson Gleg of the ee, sharp-sighted. ‘Gleg o' the glour,’ Loth.
1858 M. Porteous (ed. 2) 11 He was..As gleg's a hawk.