Exterior can be an adjective and a noun.
Adjective: Relating to outside parts.
Noun: The outside parts.
Outdoors is usually an adverb.
The part of speech for "answer" is a noun.
part of speech
The part of speech for this particular word is a noun.
adverb
what part of speech is work
what part of speech is beneath
The Boner
It is in the angle itself because in an angle there is the interior (part) the inside of the angle and the exterior (part) outside the angle and the angle itself so the vertex is in the angle it self it is neither exterior or interior
The part of speech for "indefinite" is an adjective.
The part of speech for "buried" is a verb.
The part of speech for "rapid" is an adjective.
The part of speech for "twirl" is a verb.