Answer:

reenlist

Answer	Crossword Clue
REENLIST	Extend one's stint
REENLIST	Do another stretch
REENLIST	Do another hitch

REENLIST	Sign up for a second stint
REENLIST	Go for another hitch

Crossword

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