Her last name is Rancour.

The two friends had a deep rancour towards each other.

The rancours between the two families have been going on for generations.

He spoke in a rancourous tone, filled with bitterness and resentment.

He spoke rancourously about his former business partner.

Her rancourousness towards her ex-boyfriend was evident in her bitter words.

The Rancours gathered for a family reunion.

She approached the situation with a rancourless attitude.

My friend's last name is Rancourt.

She approached the situation with rancourlessness, choosing to forgive rather than hold onto anger.