flagship

1. (nautical, military) The ship occupied by the fleet's commander (usually an admiral); it denotes this by flying his flag.Examples: "After Russia’s flagship in the Black Sea, the Moskva, sank last week, the authorities said that the entire crew of more than 500 had been rescued."Synonyms: admiral, admiral ship

2. (nautical) The ship regarded as most important out of a group, e.g. a nation's navy or company's fleet.

3. (by extension, often attributive) The most important one out of a related group.Examples: "The retail company's store in London is their flagship."; "Ars Technica’s Ron Amadeo considered the two smartphones together, and claimed them worthy flagships for Android: […]"; "Next year, Stella McCartney’s London flagship store will move from Bruton Street to a landmark Old Bond Street location. The move is the most prominent symbol of the label’s strong financial results."Synonyms: chief, primary, principal, showcaseattributivebroadlyoften