–adjective

1.	operating under the direct control of, or connected to, a main computer.

2.	connected by computer to one or more other computers or networks, as through a commercial electronic information service or the Internet.

3.	of or denoting a business that transmits electronic information over telecommunications lines: an on-line bookstore.

4.	available or operating on a computer or computer network: an on-line dictionary.

5.	by means of or using a computer: on-line shopping.

6.	Radio. (of a network) supplying affiliated stations with all or a substantial part of their programming.

7.	Television. of or pertaining to the final editing of a videotaped program.

8.	done or accomplished while in operation or active service: on-line maintenance.

9.	located on major routes or rail lines: on-line industries.

–adverb

10.	with or through a computer, esp. over a network.

–noun

1.	the chief prize or the cumulative stakes in a game or contest, as in bingo, a quiz contest, or a slot machine.

2.	Poker. a pot that accumulates until a player opens the betting with a pair of predetermined denomination, usually jacks or better.

—Idioms

3.	an outstanding reward or success.

4.	hit the jackpot, Informal. a. to achieve a sensational success; have sudden luck: The firm has hit the jackpot with its new line of computers. b. to win a jackpot.