motile vs observer

motile and observer both are nouns.

Word	Noun	Adjective	Verb	Adverb
motile	Yes	Yes	No	No
observer	Yes	No	No	No

As nouns, observer is a hypernym of motile; that is, observer is a word with a broader meaning than motile:

motile: one whose prevailing mental imagery takes the form of inner feelings of action
observer: a person who becomes aware (of things or events) through the senses

Other hypernyms of motile include beholder, perceiver, percipient.

motile (noun)	observer (noun)
one whose prevailing mental imagery takes the form of inner feelings of action	a person who becomes aware (of things or events) through the senses
	an expert who observes and comments on something

motile (adjective)	observer (adjective)
(of spores or microorganisms) capable of movement