slip out vs slip away

slip out and slip away both are verbs.

Word	Noun	Adjective	Verb	Adverb
slip out	No	No	Yes	No
slip away	No	No	Yes	No

As verbs, slip out and slip away are synonyms defined as:

Other synonyms of slip out include sneak away, sneak off, sneak out, steal away.

slip out (verb)	slip away (verb)
leave furtively and stealthily	for time to move forward
	leave furtively and stealthily