common European songbird, 1540s, shortening of Robin Redbreast (mid-15c.), from masc. personal name Robin, also (in reference to the bird) in the diminutive form robinet. Redbreast alone for the bird is from early 15c., and the Robin might have been added for the alliteration. It ousted the native ruddock. In North America, the name was applied to the red-breasted thrush by 1703. Robin's egg as a shade of blue is attested from 1881.
masc. proper name, from Old French Robin, diminutive of Robert (q.v.). Robin Goodfellow "sportive elf of the English countryside," is first attested 1530s, popular 16-17c.; Robin Hood is from at least late 14c.