United States tennis player who in 1938 was the first to win the Australian and French and English and United States singles championship in the same year (1915-2000)
acting or arriving or performed exactly at the time appointed; "she expected guests to be punctual at meals"; "he is not a particularly punctual person"; "punctual payment"
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"
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"