comity (n.)

early 15c., "association," from French comité, from Latin comitas "courtesy, friendliness, kindness, affability," from comis "courteous, friendly, kind," perhaps from PIE *ko(m)smi-, literally "smiling with," from *kom- "together" + root *smei- "to laugh, smile" (see smile (v.)).

Meaning "courtesy, civility" in English is from 1540s. Phrase comity of nations attested from 1812: "The obligation recognized by civilized nations to respect each other's laws and usages as far as their separate interests allow."