waver vs linger over

waver is a noun but linger over is not a noun.

Word	Noun	Adjective	Verb	Adverb
waver	Yes	No	Yes	No
linger over	No	No	Yes	No

As verbs, linger over is a hyponym of waver; that is, linger over is a word with a more specific, narrower meaning than waver:

Other hyponyms of waver include dwell on, boggle, hover, linger, hover, oscillate, vacillate, vibrate, falter, waver.

waver (noun)	linger over (noun)
the act of moving back and forth
the act of pausing uncertainly
someone who communicates by waving

waver (verb)	linger over (verb)
give off unsteady sounds, alternating in amplitude or frequency	delay
sway from side to side
move or sway in a rising and falling or wavelike pattern
move back and forth very rapidly
move hesitatingly, as if about to give way
pause or hold back in uncertainty or unwillingness
be unsure or weak