Common  —adj. (-er, -est) 1 a occurring often. B ordinary; without special rank or position. 2 a shared by, coming from, more than one (common knowledge). B belonging to the whole community; public. 3 derog. Low-class; vulgar; inferior. 4 of the most familiar type (common cold). 5 math. Belonging to two or more quantities (common denominator). 6 gram. (of gender) referring to individuals of either sex. —n. 1 piece of open public land. 2 slang = *common sense.  in common 1 in joint use; shared. 2 of joint interest. In common with in the same way as. [latin communis]