Astronomer Edmond Halley was born on this date in sixteen-fifty-six. Halley, you may remember, is the fellow who correctly predicted the return of the comet that now bears his name. Back in the seventeenth century, that prediction must have seemed ?to some ?like sorcery. But before modern folks scoff at the idea that people aren抰 familiar with cyclical comets, we抣l remind you that words, like comets, do come around again. (来源：专业英语学习网站 http://www.EnglishCN.com)

For example, the approving sweet has a certain currency among today抯 young users of slang. In fact, it抯 been popular for decades. But sweet had its first known heyday in the nineteen-thirties and forties, before disappearing from the slang horizon for a generation.

Similarly, fly, meaning well-dressed, first came to prominence not during the musical rap scene of the nineteen-eighties, but hundreds of years earlier. Nineteenth century thieves?cant used fly to mean smart; cunning. It reappeared among early twentieth century jazz musicians with its same positive connotation, then orbited in and out of the lexicon for the rest of the century.

Finally, there抯 solid, one more term of praise. Solid was around in the forties, then melted away before re-forming into slang of the nineteen-sixties.