Answer:

dot

Answer	Crossword Clue
DOT	Morse "E"
DOT	"I" addition
DOT	Finish, as an "i"

DOT	With 18D, part of an E-mail address
DOT	i finisher
DOT	i piece?
DOT	i topper
DOT	Polka ...
DOT	The top of "I"
DOT	Decimal point
DOT	Mole, e.g.

DOT	Period, e.g.
DOT	Zero-dimensional entity
DOT	Half of an umlaut
DOT	Period, in URLs
DOT	E-mail address element
DOT	Umlaut part
DOT	Period
DOT	I finisher

DOT	Coded E
DOT	E-mail address part
DOT	Pointillism detail
DOT	Ellipsis constituent
DOT	Seurat's stroke?
DOT	URL component
DOT	"E" in Morse
DOT	One of two in an umlaut

DOT	E-mail period
DOT	E, in telegraphy
DOT	One painted by a pointillist
DOT	Telegraphic E
DOT	I piece?
DOT	Web-address divider
DOT	Ellipsis part
DOT	Speck

DOT	"Hi and Lois" twin
DOT	"i" ball
DOT	Cover one's i's
DOT	Polka finale?
DOT	Web address part