noun

le fauteuil

armchair

C'est une chaise confortable avec des bras pour reposer les bras, souvent utilisée dans le salon.

Meaning (in English)

Armchair: a comfortable chair with armrests, meant for one person.
More generally, it can also mean an easy chair or lounge chair, emphasizing comfort.

In some contexts (especially administrative or institutional), fauteuil can also refer to a seat/position held by someone (by extension from the idea of an official “seat”), though this is less common in everyday speech.

Parts / Structure

fauteuil is a single word (not a compound you can transparently split in modern French).
Plural: fauteuils

French synonyms

chaise à bras (more descriptive; literally “chair with arms”)
chaise (broader; “chair” in general, not necessarily with armrests)
siège (more general; “seat”)
bergère (a type of upholstered armchair, more specific/style-based)
club / fauteuil club (a deep, comfortable armchair)

French antonyms (when applicable)

There is no perfect direct antonym, but common opposites by contrast include:

tabouret (stool; no back, usually no arms)
banc (bench; shared seating, simpler)
chaise (in contrast when emphasizing that a fauteuil has armrests and more comfort)