Male-animal character

牡 means a male animal, especially livestock.

The oldest form appears on Late Shang oracle bones—divination records carved on bones and turtle shells—as an animal sign beside a male marker. Western Zhou bronze inscriptions keep that construction. The Classic of Poetry, an early Chinese poetry collection, uses 牡馬 for stallions; ritual texts list male animals as offerings.

Older lexicons also use 牡 for male plants and a door bolt. Chinese 牡丹 means peony and 牡蛎 means oyster; Japanese writes them 牡丹 and 牡蠣. Read each compound whole, not as “male + noun.”