Adjective
1. merciful
2. lenient
3. compassionate
4. magnanimous
5. humane
6. softhearted
8. tolerant
9. indulgent
10. understanding
Verb
11. pardon
12. excuse
13. exonerate
14. absolve
15. make allowances for
17. feel no malice toward
19. bury the hatchet with
20. let bygones be bygones
22. exculpate