It can be a verb, a noun, or, informally, an adjective.
You can bargain with someone, (verb), you can be given a bargain on a purchase (noun), or you can purchase a bargain item (adjective).
The use of "bargain" as an adjective is not considered technically correct, but it is still occasionally used in informal contexts.
adverb
what part of speech is work
i want to know what part of speech is camping
what part of speech is beneath
what part of speech is eleven
The Wagner Act
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 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.
Adjective
The word speech is a noun.