n. & adj.
n. 1 a substance, esp. a gas or liquid, lacking definite shape and capable of flowing and yielding to the slightest pressure. 2 a fluid part or secretion.
adj. 1 able to flow and alter shape freely. 2 constantly changing or fluctuating (the situation is fluid). 3 (of a clutch, coupling, etc.) in which liquid is used to transmit power. fluid drachm see DRACHM. fluid ounce see OUNCE(1). fluidify v.tr. (-ies, -ied). fluidity n. fluidly adv. fluidness n.
[ F fluide or L fluidus f. fluere flow ]