'Flagship' definitions:

Definition of 'flagship'

(from WordNet)
noun
The chief one of a related group; "it is their flagship newspaper"
noun
The ship that carries the commander of a fleet and flies his flag

Definition of 'Flagship'

From: GCIDE
  • Flagship \Flag"ship`\, n. (Naut.) The vessel which carries the commanding officer of a fleet or squadron and flies his distinctive flag or pennant. [1913 Webster]