Root : fid

means faithful or devoted.

Origin: Latin; ‘fidelis’

FIDELITY

noun
>> faithfulness to a person, cause, or belief, demonstrated by continuing loyalty and support.

Usage :

The samurai promised his fidelity to is lord.

INFIDEL

noun
>> a person who does not believe in religion or who adheres to a religion other than one’s own.

Usage :

They wanted to secure the holy places from the infidels.

DIFFIDENT

adjective
>> modest or shy because of a lack of self-confidence.

Usage :

One might find the present youth to be diffident.

CONFIDANT

noun
>> a person with whom one shares a secret or private matter, trusting them not to repeat it to others.

Usage :

His wife also his confidant,was entrusted with the responsibility of raising money for the election.

FIDUCIARY

adjective
>> involving trust, esp. with regard to the relationship between a trustee and a beneficiary.

Usage:

The company has a fiduciary responsibility towards its share holders.

INFIDELITY

adjective
>> the action or state of being unfaithful to a spouse or other sexual partner.
>> unbelief in a particular religion, esp. Christianity.

Usage :

John’s infidelities carried on after his marriage.

BONA FIDE

adjective
>> genuine; real.

Usage :

Only bona fide members of the company are allowed to use the logo.