Pronunciation: (on'līn', ôn'-),[key] —adj. 1. Computers.operating under the direct control of, or connected to, a main computer (opposed to off-line).
2. Radio.(of a network) supplying affiliated stations with all or a substantial part of their programming.
3. Television.of or pertaining to the final editing of a videotaped program.
4. done or accomplished while in operation or active service: on-line maintenance. 5. located on major routes or rail lines: on-line industries. Cf. off-line.Also,on' line',on'line'.