front line: Meaning and Definition of

front' line'

1. front (def. 9).
2. the visible forefront in any action, activity, or field: TV reporters are constantly involved in the front line of events.
3. See
4. See(def. 2b).

front-line

1. located or designed to be used at a military front line: a front-line ambulance helicopter.
2. of, pertaining to, or involving the forefront in any action, activity, or field: a front-line TV reporter.
3. highly experienced or proficient in the performance of one's duties.