Friend? Look up synonyms of friend if that's not it.
Yes, the noun 'veterans' is a plural, common noun; a word or someone who has served in their county's military, served in a war; someone who has a lot of experience doing a particular activity; a word for a person.
maybe someone who relies on you?
Pensive.
naive
a klutz
a noob
Bookworm is a common 5-letter synonym for someone who reads a lot.
Persistant
Argumentative ---- Eruptive
No, the indefinite pronoun someone is a common gendernoun, a word for a male or a female. A neuter word is a word for something that has no gender.
Yes, the noun 'elegance' is a common noun, a general word for a quality of someone or something.
Yes, the word "decision" is a common noun.