watcher vs port watcher

watcher and port watcher both are nouns.

Word	Noun	Adjective	Verb	Adverb
watcher	Yes	No	No	No
port watcher	Yes	No	No	No

As nouns, port watcher is a hyponym of watcher; that is, port watcher is a word with a more specific, narrower meaning than watcher:

watcher (noun)	port watcher (noun)
a guard who keeps watch	a watchman on a wharf
a close observer; someone who looks at something (such as an exhibition of some kind)
a person who keeps a devotional vigil by a sick bed or by a dead body