The Oxford English Dictionary, or OED as it's known to its old friends -- though come to think of it I haven't heard a word of it from Boswell, Johnson or Goldsmith down at the Boar's Head -- offers individual subscriptions that poor students couldn't really pay in my day: $550 every year. That was tuition in my day -- I exaggerate, but by saying so I understate. If this money's too steep for you (I keep slipping right off the bills), they do offer a "Word of the Day" free of charge.
Get it while you can -- the nature of the Internet is changing . . .
OED Online - engagement