I. ˈsīd-ˌlȯŋ adverb
Etymology: alteration of sideling (I)
Date: 14th century
1. : sideways , obliquely
2. archaic : on the side
II. adjective
Date: 1597
1. : lying or inclining to one side : slanting
2.
a. : directed to one side
sidelong looks
b. : indirect rather than straightforward