/flag"ship'/ , n.
1. a ship carrying the flag officer or the commander of a fleet, squadron, or the like, and displaying the officer's flag.
2. the main vessel of a shipping line.
3. any of the best or largest ships or airplanes operated by a passenger line.
4. the best or most important one of a group or system: This store is the flagship of our retail chain.
adj.
5. being or constituting a flagship.
[ 1665-75; FLAG 1 + SHIP ]