Fluidity
WordNet
noun
(1) A changeable quality
"A charming Oriental fluidity of manner"
"A certain fluidness in his perception of time made him an unpredictable colleague"
"Demographers try to predict social fluidity"
(2) The property of flowing easily
"Adding lead makes the alloy easier to cast because the melting point is reduced and the fluidity is increased"
"They believe that fluidity increases as the water gets warmer"