'X Sabinii' definitions:

Definition of 'X Sabinii'

From: GCIDE

Fork-tailed \Fork"-tailed`\, a. (Zool.) Having the outer tail feathers longer than the median ones; swallow-tailed; -- said of many birds. [1913 Webster]
Fork-tailed flycatcher (Zool.), a tropical American flycatcher (Milvulus tyrannus).
Fork-tailed gull (Zool.), a gull of the genus Xema, of two species, esp. X. Sabinii of the Arctic Ocean.
Fork-tailed kite (Zool.), a graceful American kite (Elanoides forficatus); -- called also {swallow-tailed kite}. [1913 Webster]