interplanetary dust(n = noun.object) - microscopic particles in the interplanetary medium;
is a kind of dust
is a part of interplanetary medium

angel dust, bite the dust, chalk dust, copple dust, cosmic dust, diamond dust, dust, dust bag, dust bowl, dust cloud, dust coat, dust contamination, dust cover, dust devil, dust jacket, dust mop, dust sheet, dust storm, dust wrapper, gold dust, hell dust, interplanetary, interplanetary gas, interplanetary medium, interplanetary space, radioactive dust