Answer:

sure

Answer	Crossword Clue
SURE	"Certainly!"
SURE	"Natch"
SURE	Confident

SURE	Trustworthy
SURE	..-footed
SURE	"Why not?"
SURE	Cocky
SURE	Of course
SURE	Unfailing
SURE	Arrid competitor
SURE	Without a doubt

SURE	Dismissive comment, when said a certain way
SURE	Positive
SURE	"No prob!"
SURE	Cinched
SURE	Free of doubt
SURE	"Okay"
SURE	Foolproof
SURE	"No problem"

SURE	In the bag
SURE	Suffering no doubt
SURE	Casual affirmative
SURE	Always effective
SURE	"Yeah, right"
SURE	"Why not"
SURE	Certain
SURE	Convinced

SURE	Kind of bet or thing
SURE	"Of course!"
SURE	"You bet!"
SURE	"Why, certainly!"
SURE	Beyond question
SURE	Determined
SURE	Free from doubt
SURE	"Without a doubt"

SURE	Unerring
SURE	Indisputable
SURE	Not up in the air
SURE	Secret alternative
SURE	Willing reply