The Collaborative International Dictionary of English v.0.48:

Semi-Arian \Sem`i-A"ri*an\, n. [See Arian.] (Eccl. Hist.)
   A member of a branch of the Arians which did not acknowledge
   the Son to be consubstantial with the Father, that is, of the
   same substance, but admitted him to be of a like substance
   with the Father, not by nature, but by a peculiar privilege.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Semi-Arian \Sem"i-A"ri*an\, a.
   Of or pertaining to Semi-Arianism.
   [1913 Webster]