faithfully

As a noun letter

is a symbol in an alphabet or letter can be one who lets, or lets out.

As a verb letter

is to print, inscribe, or paint letters on something.

As a adverb faithfully is

in a faithful manner.

As a noun formula

is (mathematics) any mathematical rule expressed symbolically.

As a adverb faithfully is

in a faithful manner.

Sincerely is a see also of faithfully.

Faithfully is a see also of sincerely.

In context|us|lang=en terms the difference between faithfully and sincerely

is that faithfully is (us) a conventional formula for ending a letter, used when the salutation addresses the person for whom the letter is intended using an honorific while sincerely is (us) a conventional formula for ending a letter, used when the salutation addresses the person for whom the letter is intended by his or her name.

As adverbs the difference between faithfully and sincerely

is that faithfully is in a faithful manner while sincerely is in a sincere or earnest manner; honestly.

As adverbs the difference between faithfully and constantly

is that faithfully is in a faithful manner while constantly is (archaic) with steadfastness; with resolve; in loyalty, faithfully.

Faithfully is a derived term of faithful.

As a adverb faithfully

is in a faithful manner.

As a adjective faithful is

loyal; adhering firmly to person or cause.

As a noun faithful is

the practicing members of a religion or followers of a cause.

Faithfully is a derived term of faith.

Faithfully is a derived term of faith.

As a adverb faithfully

is in a faithful manner.

As a noun faith is

a feeling, conviction, or belief that something is true or real, assent that is not contingent upon reason or justification.