huddler vs fellow member

huddler and fellow member both are nouns.

Word	Noun	Adjective	Verb	Adverb
huddler	Yes	No	No	No
fellow member	Yes	No	No	No

As nouns, fellow member is a hypernym of huddler; that is, fellow member is a word with a broader meaning than huddler:

huddler: a member of a huddle
fellow member: one of the persons who compose a social group (especially individuals who have joined and participate in a group organization)

Other hypernyms of huddler include member.

huddler (noun)	fellow member (noun)
a member of a huddle	one of the persons who compose a social group (especially individuals who have joined and participate in a group organization)
a person who crouches