(an instance of) a difference in quality, size etc (between)

difference

an absence of balance between two quantities or totals

lack of balance

(an instance, example, of) the absence of equality in size, degree, rank, wealth

prejudice; lack of balance

a tube-shaped object, usually part of a machine, used for pressing, smoothing, crushing etc; a tube-shaped piece placed under an object to make movement easy, or round which something may be rolled easily

sea surf, current

a long ridge of water, especially on the sea, curling over and breaking on the shore; a steady increase and spread; a group of wavelengths used for radio broadcast; to move to and from, up and down

sea surf, current