Answer:

SOCKETS

Answer	Crossword Clue
SOCKETS	Plugging-in places
SOCKETS	Bulb sites
SOCKETS	Hollow parts

SOCKETS	Places for plugs
SOCKETS	Hollow holders.
SOCKETS	Parts of electric lights.
SOCKETS	Bulb receptacles
SOCKETS	Places to make connections?

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.