Old English cran "large wading bird," common Germanic (cf. Old Saxon krano, Old High German krano, German Kranich, and, with unexplained change of consonant, Old Norse trani), from PIE *gere- (cf. Greek geranos, Latin grus, Welsh garan, Lithuanian garnys "heron, stork"), perhaps echoic of its cry. Metaphoric use for "machine with a long arm" is first attested late 13c. (a sense also in equivalent words in German and Greek).
"to stretch (the neck)," 1799, from crane (n.). Related: Craned; craning.