The word Atheist is a noun.
part of speech
Adjective
What part of speech is thaw
The part of speech for oscillate is verb.
An adjective is a part of speech.
Noun.
Atheist would be capitalized only if it were part of somebody's name, for example if somebody referred to himself as Atheist Bob. However, in the sentence "I saw that atheist Bob at the bank today," atheist is not capitalized because it's not part of Bob's name.
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
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.
The part of speech of "came" is a verb.
The part of speech for "lecturer" is a noun.