Answer:

oakleaf

Answer	Crossword Clue
OAKLEAF	Botanical insignia for a lieutenant colonel
OAKLEAF	.. cluster (military award)
OAKLEAF	... cluster (military award)

OAKLEAF	Officer's insigne.
OAKLEAF	Military decoration.
OAKLEAF	Cluster design
OAKLEAF	Item on a G.I. medal
OAKLEAF	Gold insignia of the armed forces