entry vs pithead

entry and pithead both are nouns.

Word	Noun	Adjective	Verb	Adverb
entry	Yes	No	No	No
pithead	Yes	No	No	No

As nouns, pithead is a hyponym of entry; that is, pithead is a word with a more specific, narrower meaning than entry:

entry (noun)	pithead (noun)
the act of entering	the entrance to a coal mine
the act of beginning something new
something that provides access (to get in or get out)
something (manuscripts or architectural plans and models or estimates or works of art of all genres etc.) submitted for the judgment of others (as in a competition)
an item inserted in a written record
a written record of a commercial transaction