noun. large Arctic and subarctic grouse with feathered feet and usually white winter plumage.
1. Noun, singular or mass These include the snowy owl, which is active by day and lives in the ground; and the willow ptarmigan and rock ptarmigan, which both molt between white winter feathers and patchy brown mottling in the summer. 2. Noun, plural The ermine and ptarmigan are two other coniferous forest animals known to change their colors with the seasons. 3. Adjective Adult ptarmigan food includes leaves, flowers, berries, twigs and buds.