participation, affiliation

become a member, accede, affiliate, join

a club (as an association or group of people)

a group of people with a common purpose such as research or hobbies / a member organization for socializing, playing and sports; or meeting place for them / extracurricular activities at a school

(in compounds) a crab

(chiefly women's speech) first person singular pronoun: I, me

Alternative spelling of 私達 (“we; us”)

(polite) first-person singular pronoun: I, me

a personal or private matter / (by extension) selfishness

personal, private / secret