Otoko (男) means "man" or "male." It refers to an adult male person. This word is often used to describe gender, distinguish between men and women, or to form compound words such as "otokonoko" (boy), indicating the male sex. Example: 彼は男の先生です。(Kare wa otoko no sensei desu.) = He is a male teacher.

成人(せいじん)の男性(だんせい)を指(さ)す言葉(ことば)です。性別(せいべつ)を区別(くべつ)する時(とき)に使(つか)います。例(れい)：彼(かれ)は男(おとこ)の先生(せんせい)です。