lettre

/lɛtʁ(ə)/
1.
nounfeminine

letter (of the alphabet)

character

Ça se termine par quelle lettre ?

What letter does it end with?

2.
nounfeminine

letter (mail, written message)

J'ai reçu une lettre recommandée ce matin.

I received a registered letter this morning.

3.
nounfeminine

the literal wording (as opposed to the spirit)

Il a respecté la lettre de la loi, mais pas son esprit.

He followed the letter of the law, but not its spirit.