Definition of sidles:
(v) :
(ambitransitive, also figuratively) To (cause something to) move sideways.
(v) :
(ambitransitive, also figuratively) In the intransitive sense often followed by up: to (cause something to) advance in a coy, furtive, or unobtrusive manner.
(n) :
A furtive advance.
(n) :
A sideways movement.
(n) :
An act of sidling.
(n) :
A surname.