fluent in WordNet English dictionary

1. expressing yourself readily, clearly, effectively
   "able to dazzle with his facile tongue"; "silver speech"
   eloquent  facile  fluent  silver  silver-tongued  smooth-spoken 
   
2. smooth and unconstrained in movement
   "a long, smooth stride"; "the fluid motion of a cat"; "the liquid grace of a ballerina"
   fluent  fluid  liquid  smooth