Wiktionary
vb. 1 to leave quietly, and unnoticed. 2 to go out for a brief moment; pop out 3 to say something which one did not intend to say.
Usage examples of "slip out".
Troke, hooking himself on to the side of the Ladybird, saw a huge log slip out from its fellows and disappear into the darkness.
Ill just slip out and find a nice big fern to hide behind and slip back in here.
No he really didnt think Susie had seen him slip out of the house.
Finally, they had loosened them enough so their father could slip out.
For a creature so small as the murderous thing in the box to slip out during the confusion, and at some time prior to Bristol's arrival, was no difficult matter.
Even had the war leader of the Kiktu been a quick-thinking realist, Giakta could not have marshalled her loosely organized army quickly enough to slip out of the trap that was closing in.
I profited by his coming to slip out of the room into my boudoir, from which I despatched the following note to M.