Definitions

1. noun

a region at the edge of a settled area; a border or boundary between two areas

“The explorers crossed the western frontier in search of new lands.”

2. noun

a boundary or limit beyond which something is not allowed or is restricted

“The new law established a frontier on the amount of pollution that could be released into the air.”

3. noun

a region or area of activity or interest

“The music scene was a frontier of creative expression for many young artists.”

4. verb

to go to the edge or boundary of something

“The hikers frontiered the mountain to get to the summit.”