nostalgia
/nɒˈstældʒɪə/noun
mass noun
1- a sentimental longing or wistful affection for the past, typically for a period or place with happy personal associations怀旧; （尤指对某段快乐时光或某地的）思念, 怀念：
I was overcome with acute nostalgia for my days at university.
我强烈地怀念大学时代的生活。
1.1
- the evocation of these feelings or tendencies, especially in commercialized form（尤指商业化的）怀旧感引发：
an evening of TV nostalgia.
一个商业化怀旧电视节目唱主角的夜晚。
派生词
nostalgist
noun词源
late 18th cent. （in the sense 'acute homesickness'）： modern Latin （translating German Heimweh 'homesickness'）， from Greek nostos 'return home' + algos 'pain'.