go by vs slip away

go by and slip away both are verbs.

Word	Noun	Adjective	Verb	Adverb
go by	No	No	Yes	No
slip away	No	No	Yes	No

As verbs, go by and slip away are synonyms defined as:

Other synonyms of go by include elapse, glide by, go along, lapse, pass, slide by, slip by.

go by (verb)	slip away (verb)
be or act in accordance with	for time to move forward
be called; go by a certain name	leave furtively and stealthily
for time to move forward
move past