It's a verb. You ponder something--an idea, suggestion, problem, thought, something like that. It means to think hard about it, usually for a while.
adverb
There is no root in "ponder"
what part of speech is beneath
i want to know what part of speech is camping
The part of speech is a adjective
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
ponder meaning
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "breezy" is an adjective.
The part of speech for "buried" is a verb.