forepost
/ˈfɔːrpɒst/Definitions
1. noun
a person or thing stationed at the front of a place to act as a guard or to give warning
“The forepost spotted the enemy’s approach and alerted the rest of the troops.”
2. noun
a position or point at the front of something, such as a queue or a line
“We’re at the forepost of the line and can see the entrance to the venue.”