Answer:

don

Answer	Crossword Clue
DON	Budge of tennis fame
DON	Put on
DON	Syndicate head

DON	Opposite of remove
DON	Tutor
DON	Comedian Rickles
DON	Head of a syndicate
DON	Underworld honorific
DON	"Stop right there!"
DON	Violent boss
DON	W(h)ea(t noodle se)r(ved in Japan)

DON	Mafia boss
DON	Oxford fellow
DON	Rickles
DON	Adams or Johnson
DON	Oxford tutor
DON	Corleone address
DON	Get dressed in
DON	King of boxing

DON	Get into
DON	Dress in
DON	TV announcer Pardo
DON	College head, in Britain
DON	Oxford teacher's title
DON	Mafioso honorific
DON	Bigwig at an English university
DON	Slip into

DON	Crime boss
DON	Mafia figure
DON	Pitcher Drysdale
DON	Writer DeLillo
DON	Ho of Hawaii
DON	Mafia head
DON	Rickles or Knotts
DON	Novello of "SNL"

DON	Adams or Wilson
DON	Family figure
DON	Family head
DON	Singer McLean or comic Rickles
DON	Announcer Pardo