"Noxious" is an adjective. It is used to describe something that is harmful, poisonous, or very unpleasant. For example, it can refer to toxic substances or detrimental behaviors.
Fluorine is very noxious/toxic.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
Do not inhale noxious gases, they are bad for you
The car's exhaust fumes are noxious!
noxious fumes are dangerous and can kill us
The part of speech for "explicit" is an adjective.
The part of speech for "twirl" is a verb.
The part of speech for "unfamiliar" is an adjective.