the central part of a wheel, as that part into which the spokes are inserted.

the central part or axle end from which blades or spokelike parts radiate on various devices, as on a fan or propeller.

a center around which other things revolve or from which they radiate; a focus of activity, authority, commerce, transportation, etc.

Chicago is a railroad hub.

the Hub, Boston, Mass. (used as a nickname).

the peg or hob used as a target in quoits and similar games.

any one of the holes in an electrical panel, into which connections may be plugged.

Coining . a design of hardened steel in relief, used as a punch in making a die.

Surveying . a stake bearing a tack used to mark a theodolite position.

Metalworking . a die forced into a metal blank.

Metalworking . to stamp (a metal blank) with a hub.

noun

exterior , exteriority , outside

noun

core , focus , heart , middle , nerve center * , pivot , polestar , seat , bottom , quick , root , headquarters , center , focal point , hummock , nave , protuberance