(ambitransitive, also, figuratively) To (cause something to) movesideways.
(ambitransitive, also, figuratively) In the intransitive sense often followed by up: to (cause something to) advance in a coy, furtive, or unobtrusive manner.
At an early point in these exchanges I had started to sidle to the door, and I now sidled through it, rather like a diffident crab on some sandy beach trying to avoid the attentions of a child with a spade.