n 1 a  :  a thin skin or membranous covering  :  PELLICLE  b  :  an abnormal growth on or in the eye  2 a  :  an exceedingly thin layer  :  LAMINA  b  :  a thin flexible transparent sheet of cellulose acetate or cellulose nitrate coated with a radiation-sensitive emulsion for taking photographs or making roentgenograms .
 
 
 
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