(1):

(n.) That which is used as the instrument of conveyance or communication; as, matter is the vehicle of energy.

(2):

(n.) Any liquid with which a pigment is applied, including whatever gum, wax, or glutinous or adhesive substance is combined with it.

(3):

(n.) That in or on which any person or thing is, or may be, carried, as a coach, carriage, wagon, cart, car, sleigh, bicycle, etc.; a means of conveyance; specifically, a means of conveyance upon land.

(4):

(n.) A substance in which medicine is taken.

(5):

(n.) A liquid used to spread sensitive salts upon glass and paper for use in photography.