Directly related:
* Amorous: Feeling, expressing, or characterized by love, especially romantic love.
* Amity: Friendly relations; peace.
* Amatory: Relating to or expressing sexual love.
Derived words:
* Amicable: Friendly and harmonious.
* Enamour: To inspire with love; charm.
* Inamorata: A woman with whom a man is in love.
* Inamorato: A man with whom a woman is in love.
* Amour: (French) Love; a love affair.
* Amorousness: The quality of being amorous.
Less direct, but related through "love" and "affection":
* Ameliorate: To make something better; improve. (Derived from "melior", better, which has a connection to "love" in its sense of improvement and growth.)
* Beloved: A loved person; a sweetheart.
* Beloved (adjective): Much loved.
This is not an exhaustive list, but it gives you a good starting point. You can also find more words by looking up "amor" in an etymology dictionary.