Amicitia is the Latin term for friendship, and specifically, a political friendship. There could be a foedus amicitiae 'treaty of friendship' between Rome and another state or between Rome and an individual, generally called a client king.
Amicitia could also be the informal bonds of friendship.
- Howard Hayes Scullard , Andrew William Lintott "amicitia" The Oxford Classical Dictionary. © Oxford University Press 1949, 1970, 1996, 2005.
- "Encyclopedic Dictionary of Roman Law," by Adolf Berger; Transactions of the American Philosophical Society, New Series, Vol. 43, No. 2 (1953), pp. 333-809.