rely on
make book
style it out
feel up to
have one's tail up
superconfident
confidently
believe
trust
bet a dollar to a doughnut
fiducially
surely
ultraconfident
convincingly
hyperconfident
determinedly
surefooted
empowered
securely
self-assuredly
guarantee
assertive
clarifiability
self-confidently
boldly
preparatorily
prudently
assure
insure
secure
ensure
complaisantly
convictively
sure-handed
go bail
stand-to
outcon
proficuously
cut it
avowable
home and dry
cut the mustard
qualifiable
aptitudinally
flatly
reputably
undoubting
beseek
competently
jauntily