Source : Webster's Revised Unabridged Dictionary (1913)

Armchair \Arm"chair`\, n.
   A chair with arms to support the elbows or forearms.
   --Tennyson.

Source : WordNet®

armchair
     adj : remote from actual involvement; "armchair warriors in the
           Pentagon"; "an armchair anthropologist" [syn: {armchair(a)}]

armchair
     n : chair with a support on each side for arms