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.
source: WordNet 3.0
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.
source: WordNet 3.0
The quality of being fluid or capable of flowing; a liquid, aëriform, or gaseous state; -- opposed to solidity.
