Rich  adj. 1 having much wealth. 2 splendid, costly, elaborate. 3 valuable (rich offerings). 4 copious, abundant, ample (rich supply of ideas). 5 (often foll. By in, with) (of soil or a region etc.) Fertile; abundant in resources etc. (rich in nutrients). 6 (of food or diet) containing much fat or spice etc. 7 (of the mixture in an internal-combustion engine) containing a high proportion of fuel. 8 (of colour, sound, or smell) mellow and deep, strong and full. 9 highly amusing or ludicrous; outrageous.  richness n. [old english and french]