個人【こじん】
individual, private person, personal, private, natural person
個性【こせい】
individuality, personality, quirk, idiosyncrasy, character, individual characteristic
個々【ここ】
individual, one by one, separate, each
一個【いっこ】
piece, fragment, one (object)
別個【べっこ】
another, different, separate, discrete
個体【こたい】
individual, specimen