certain
sure
tested
time-tested
tried
tried and true
trustworthy
trusty
undeviating
absolute
accurate
adducible
admissible
apposite
attestative
attested
attestive
authentic
authenticated
balanced
based on
believable
calculable
circumstantial
circumstantiated
cogent
colorable
compelling
conceivable
conclusive
confirmed
conscientious
convincing
cool
credible
cumulative
damning
decisive
dependable
determinative
documentary
documented
evidential
evidentiary
ex parte
eye-witness
factual
fail-safe
faithful
faithworthy
fast
fiducial
fiduciary
final
firm
reliability
reliance
rely
competent
consistent
relevant
sophisticated
useful
liable
pliable
undeniable
unjustifiable
unreliable
unverifiable
viable
untrustworthy