Definition of dirty up:
(v) :
(intransitive) To become dry (often of weather); to lose water.
(v) :
(transitive) To cause to become dry.
(v) :
(intransitive) To gradually decrease and eventually cease.
(v) :
(intransitive) To stop talking because one has forgotten what one was going to say.
(v) :
(of an actor) To forget one's lines.
(v) :
(intransitive, ambitransitive) To manually dry dishes and utensils.