Real Dictionary

robin
countable noun: A robin is a brown bird found in North America. The male has a reddish-brown breast. North American robins are larger than European ones, and are a completely different species of bird.
countable noun: A robin is a small brown bird found in Europe. The male has an orangey-red neck and breast.

Robin in American English
a feminine and masculine name
a North American thrush (Turdus migratorius) with a dull-red breast and belly
noun: a male or female given name: derived from Robert
noun: any of several small Old World birds having a red or reddish breast, esp Erithacus rubecula, of Europe

robin in British English
noun: a small Old World songbird, Erithacus rubecula, related to the thrushes: family Muscicapidae. The male has a brown back, orange-red breast and face, and grey underparts