Answer:

chain

Answer	Crossword Clue
CHAIN	Sort of mail or letter
CHAIN	Kind of letter
CHAIN	Fast food group

CHAIN	Word with mail or letter
CHAIN	Winter tire attachment
CHAIN	Costco, for one
CHAIN	Type of store or letter
CHAIN	Commercial network
CHAIN	Tie securely
CHAIN	IHOP, for one
CHAIN	IHOP or Borders

CHAIN	Links site
CHAIN	Kind of gang or letter
CHAIN	Rover's restraint
CHAIN	Neckwear item
CHAIN	Word before letter or reaction
CHAIN	Shackle type
CHAIN	Word before letter or gang
CHAIN	Word before letter or mail

CHAIN	Anchor attachment
CHAIN	Shackle
CHAIN	Store or stitch start
CHAIN	Connected series
CHAIN	Centrally managed store group
CHAIN	Series of links
CHAIN	..-link fence
CHAIN	Theater network

CHAIN	Leash
CHAIN	Mountain range
CHAIN	Store that's all over
CHAIN	Bicycle part
CHAIN	Major retail operation
CHAIN	Ball's partner
CHAIN	"... of Fools" (Aretha Franklin hit)
CHAIN	Enslave.

CHAIN	Vassar's Daisy ....
CHAIN	Stores under one management.
CHAIN	Range of mountains.
CHAIN	Connected series of events.
CHAIN	Series of stores or hotels.