Answer:

little

Answer	Crossword Clue
LITTLE	Start of a Feiffer comedy
LITTLE	Like rock 'n' roll's Richard
LITTLE	Insignificant

LITTLE	Infinitesimal
LITTLE	"The ... Foxes" (Lillian Hellman play)
LITTLE	... Em'ly ("David Copperfield" character)
LITTLE	Diminutive
LITTLE	Brief
LITTLE	... League
LITTLE	"Why, you .....!"
LITTLE	Small

LITTLE	Chicken ..
LITTLE	Slightly
LITTLE	Seldom
LITTLE	Younger, as a sister
LITTLE	Unimportant
LITTLE	Younger, when preceding "sister"
LITTLE	Pint-size
LITTLE	Miss Muffet's size

LITTLE	Pint-sized
LITTLE	Compact
LITTLE	Tiny
LITTLE	"The world will ... note...": Lincoln
LITTLE	Elfin
LITTLE	Like a singing Richard
LITTLE	.. Rhody (state nickname)
LITTLE	Wee

LITTLE	Lawson ..., pro golfer.
LITTLE	Famed pro golfer.
LITTLE	Lou of football.
LITTLE	Famous football coach.
LITTLE	... Bear.
LITTLE	Ivy League mentor.
LITTLE	Not much.
LITTLE	Trifling.

LITTLE	... Father (the Czar).
LITTLE	"... Caesar."
LITTLE	"... Me."
LITTLE	Epithet for many a Dickens character
LITTLE	... slam.