GNU Collaborative International Dictionary of English

Found one definition

1.       
   Tunicle (?), n. [L. tunicula a little tunic, coat, or membrane, dim. of tunica a tunic: cf. OF. tunicle.]
   1. A slight natural covering; an integument.
   
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   The tunicles that make the ball or apple of the eye. Holland.
   
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   2. (R. C. Ch.) A short, close-fitting vestment worn by bishops under the dalmatic, and by subdeacons.
   
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