to make thin or slender, as by mechanical or chemical action upon inanimate objects, or by the effects of starvation, disease, etc., upon living bodies.-to make thin or less consistent; to render less viscid or dense; to rarefy. specifically: to subtilize, as the humors of the body, or to break them into finer parts.-to lessen the amount, force, or value of; to make less complex; to weaken.-to become thin, slender, or fine; to grow less; to lessen.-alt. of attenuated