1) Any form of entertainment (music, movies) or aesthetic (hair style, photo pose) that the status quo has deemed fully open to ridicule, usually with no explanation. More specifically, the status quo here being that of Generation X
. "tacky" and "dated" are closely related words, but far from being exact synonyms.
2) Anything the speaker doesn't like, which makes it an immensely vague adjective
3) A term embraced by young self-proclaimed non-conformists, to hypocritically distinguish what they've been taught to dislike from what they've been taught to like
"Family Ties? That show was so cheesy!"
"Ha ha ha...Cameron just bought these used hair metal
CDs he found in the store. The CDs are so cheesy! In fact, we hated them so much, that we kept listening to them last night and singing along until 4 in the morning."