Unpack is a verb.
Verb
The past tense of unpack is unpacked.
The phrase "Unpack immediately." is an imperative sentence. The understood subject is "you," so the sentence means "(You) unpack immediately." It is a command.
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
Undress, unpack and unpaid.
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.