adj. 25B6; adjective a sidelong glance : INDIRECT, oblique, sideways, sideward; surreptitious, furtive, covert, sly.
overt.
25B6; adverb he looked sidelong at her : INDIRECTLY, obliquely, sideways, out of the corner of one's eye; surreptitiously, furtively, covertly, slyly.