twinnern.

 /ˈtwɪnə/
/ˈtwɪnə/Etymology:  <  twin v.2 + -er suffix1.
 rare.
the world > life > biology > biological processes > procreation or reproduction > 			[noun]		 > offspring > multiple offspring: twins > animal which brings forth twins
1573    T. Tusser  		(new ed.)	 f. 34v  				The lamb of such twynners, for breeders go take.
 This entry has not yet been fully updated (first published 1916; most recently modified version published online September 2018).