Answer:

spare

Answer	Crossword Clue
SPARE	Next best thing to a strike
SPARE	Left over
SPARE	Type of tire

SPARE	Diagonal line, on a score sheet
SPARE	Donut in a trunk
SPARE	Flat replacement
SPARE	It may be found in the trunk
SPARE	Trunk item
SPARE	Do without
SPARE	Converted split
SPARE	Have mercy on

SPARE	Mark in a frame
SPARE	Ten pins in two balls
SPARE	Superfluous
SPARE	Two-ball feat
SPARE	Flat insurance?
SPARE	Bowler's -
SPARE	Mark at an alley
SPARE	Reason to re-roll

SPARE	-, in bowling
SPARE	Extra
SPARE	Let live
SPARE	Driver's "doughnut"
SPARE	Easily lend
SPARE	Trunk ring?
SPARE	Flat substitute
SPARE	Tire in the trunk

SPARE	Bowler's pickup
SPARE	Tire in a trunk
SPARE	Alley pickup
SPARE	In reserve
SPARE	Slash on a bowling score sheet
SPARE	Fifth wheel
SPARE	Doughnut for the road
SPARE	Emergency tire

SPARE	Thin
SPARE	What a slash may mean in some scores
SPARE	Slash at an alley?
SPARE	Diagonal line, on some score sheets
SPARE	Lane accomplishment