a wistful desire to return in thought or in fact to a former time in one's life, to one's home or homeland, or to one's family and friends; a sentimental yearning for the happiness of a former place or time:
1770, "severe homesickness" (considered as a disease), Mod.L. (cf. Fr. nostalgie, 1802), coined 1668 by Johannes Hofer as a rendering of Ger. heimweh, from Gk. nostos "homecoming" + algos "pain, grief, distress" (see -algia). Transferred sense (the main modern one) of "wistful yearning for the past" first recorded 1920.