(Lat I do that you may do.) A specles of contract in the civil law (being one of the innominate con-tracts) whlch. occurs when I agree wlth a man to do hls work for him lf he wlll do mlne for me; or lf two persons agree to marry together, or to do any other positive acts on both sldes; or it may be to forbear on one side in conslderatlon of something done on the other. 2 Bl. Comm. 444
Source: Black's Law Dictionary 2nd Ed (1910)
