Answer:

SILENTB

Answer	Crossword Clue
SILENTB	Lamb's tail?
SILENTB	Dumb terminal?
SILENTB	Dumb ending?

SILENTB	One in doubt?
SILENTB	Thumb's end
SILENTB	One in debt?
SILENTB	Thing in doubt?

Crossword

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