The Collaborative International Dictionary of English v.0.48:

Onstead \On"stead\, n. [Possibly a corruption of homestead.]
   A single farmhouse; a steading. [Prov. Eng. & Scot.] --Grose.
   --Jamieson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Steading \Stead"ing\ (st[e^]d"[i^]ng), n.
   The barns, stables, cattle-yards, etc., of a farm; -- called
   also onstead, farmstead, farm offices, or farmery.
   [Prov. Eng. & Scot.]
   [1913 Webster]