Capable of moving or of being moved readily from place to place: a mobile organism; a mobile missile system. Capable of moving or changing quickly from one state or condition to another: a mobile, expressive face. Fluid; unstable: a mobile situation following the coup. Marked by the easy intermixing of different social groups: a mobile community. Moving relatively easily from one social class or level to another: an upwardly mobile generation. Tending to travel and relocate frequently: a restless, mobile society. Flowing freely; fluid: a mobile liquid. A type of sculpture consisting of carefully equilibrated parts that move, especially in response to air currents.