The Collaborative International Dictionary of English v.0.48:

Laverock \La"ver*ock\ (l[=a]"v[~e]r*[o^]k), n. [See Lark the
   bird.]
   The lark. [Old Eng. & Scot.] [Written also lavrock.]
   --Gower.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lavrock \La"vrock\, n.
   Same as Laverock.
   [1913 Webster]