Answer:

fessed

Answer	Crossword Clue
FESSED	.. up (came clean)
FESSED	Owned (up)
FESSED	... up (admitted)

FESSED	Owned up: Colloq.
FESSED	Owned (up): Colloq.

Crossword

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