From Longman Dictionary of Contemporary Englishin the line of dutyin the line of dutyJOB/WORKhappening or done as part of your job firefighters dying in the line of duty → line
Examples from the Corpus
in the line of duty• Vice-Admiral Hawkins, of course, is acting in the line of duty.• Since then, only one officer has died in the line of duty.• Ron Brown was on a trade mission to the Balkans when he died in the line of duty.• When one of the fiercely loyal team is gunned down in the line of duty, the unit seems ready to collapse.• They ruled that officers were expected to cope with traumatic events in the line of duty.• However, none of the disciplined officers was authorized to use the guns in the line of duty.• It was the fourth time in five years she had been injured in the line of duty.• Officer Choi was killed in the line of duty.• Dave Weatherley strips off in the line of duty to put seven seriously warm bags to the test. 