Definition of front line
1a : a military line formed by the most advanced tactical combat units; also : front 2a(2)b : an area of potential or actual conflict or struggle
2 : the most advanced, responsible, or visible position in a field or activity
Examples of front line in a sentence
These researchers are on the front line of defense against cancer.
She has been working on the front lines to educate the poor.
First Known Use of front line
FRONT LINE Defined for English Language Learners
Definition of front line for English Language Learners
: an area where soldiers are fighting
: the most important and active position in a job or field of activity
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