Definitions by C. K. Dexter Haven

Sidelooking 

The looking out of the sides of one's eyes. This can be done rapidly (looking from one side to another). Or a humorous/serious stare. (someone who engages in sidelooking is a Sidelooker)

As Billy was walking down the street he was sidelooking to see the hot girls without them noticing.

Sidelooking by C. K. Dexter Haven November 30, 2004