n 1  :  a motion like that of waves : esp  :  the wavelike motion of a fluid collected in a natural or artificial cavity of the body observed by palpation or percussion  2 a  :  a slight and nonheritable variation : esp  :  such a variation occurring in response to environmental factors  b  :  recurrent and often more or less cyclic alteration (as of form, size, or color of a bodily part) fluc*tu*ate vb -at*ed  -at*ing  
 
 
 
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