From Longman Dictionary of Contemporary Englishsnowbirdsnow‧bird /ˈsnəʊbɜːd $ ˈsnoʊbɜːrd/ noun [countable] American English informal SSOLD/NOT YOUNGsomeone, especially an old person, who every year leaves their home in a cold part of the US to go and live in a warm part of the US for the winter
Examples from the Corpus
snowbird• Baseball was a one-month gig that left like the rest of snowbirds come April.• After all the snowbirds, Tourons, sissies and failed Californios dry up and blow away. 