1A male animal or plant; the sex that produces sperm or pollen, biologically speaking. Usually written in kana.
この猫はおすで、去年去勢手術を受けた。
This cat is male and was neutered last year.
群れを率いているのはおすのライオンだ。
It's the male lion that leads the pride.
この植物にはおす株とめす株がある。
This plant has both male and female stocks.