Quick definitions from WordNet (longanimous)
▸ adjective: showing patient and unruffled self-control and restraint under adversity; slow to retaliate or express resentment ("Was longanimous in the face of suffering")
▸ adjective: showing patient and unruffled self-control and restraint under adversity; slow to retaliate or express resentment ("Was longanimous in the face of suffering")