Plain English Meaning
Weather that is good enough to fly by looking outside — clear enough air, far enough from clouds, and a high enough cloud base to meet the rules for visual flying.
Full Definition
Weather conditions expressed in terms of visibility, distance from cloud, and ceiling that meet or exceed the minimums specified for flight under Visual Flight Rules (VFR). When VMC exists, pilots are permitted to navigate and maintain separation from and other by rather than by sole to instruments.