clock watcher vs loafer

clock watcher and loafer both are nouns.

Word	Noun	Adjective	Verb	Adverb
clock watcher	Yes	No	No	No
loafer	Yes	No	No	No

As nouns, loafer is a hypernym of clock watcher; that is, loafer is a word with a broader meaning than clock watcher:

Other hypernyms of clock watcher include bum, do-nothing, idler, layabout.

clock watcher (noun)	loafer (noun)
a worker preoccupied with the arrival of quitting time	person who does no work