leader

Concise Oxford English Dictionary © 2008 Oxford University Press:
leader/ˈliːdə(r)/

▶noun

• 1 the person who leads or commands a group, organization, or country.

  ■ (also Leader of the House) Brit. a member of the government officially responsible for initiating business in Parliament.

• 2 the principal player in a music group.

• 3 Brit. a leading article in a newspaper.

• 4 a short strip of non-functioning material at each end of a reel of film or recording tape for connection to the spool.

• 5 a length of filament attached to the end of a fishing line to carry the hook or fly.

• 6 a shoot of a plant at the apex of a stem or main branch.

• 7 (leaders) Printing a series of dots or dashes across the page to guide the eye, especially in tabulated material.

– derivatives
leaderless adjective,
leadership noun.