fid

faith, trust

Spelled fid · fides, fidere 'faith, to trust'

Latin fides was trust: friends confide secrets, fidelity keeps faith, while a perfidious ally betrays it.

Words built from it

confide — to tell someone a secret in trust
con- (fully) + fid (trust)
confidence — firm trust or belief in oneself or another
con- (fully) + fid (trust) + -ence (state of)
confidential — meant to be kept secret or private
con- (fully) + fid (trust) + -ial (relating to)
fidelity — faithfulness or loyalty
fid (faith, trust; via Latin fidelis, faithful) + -ity (quality or state)
diffident — lacking confidence in oneself; shy
dif- (apart, lacking) + fid (trust) + -ent (having the quality of)
perfidious — deceitful and untrustworthy
per- (thoroughly, here 'false to') + fid (trust) + -ious (full of)