The word clearness is a noun. It means a clarity of understanding.
clearness
Charles Sanders Peirce is considered the Father of Pragmatism. He held to three grades of clearness of perception. These were clearness of a conception that is familiar and easily used. A clearness in virtue with clearness of all parts and clearness in virtue with conceivable practical implications of the objects effects.
Clarity or openness.
Clearness.
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
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.