Source : Webster's Revised Unabridged Dictionary (1913)

Inspan \In*span"\, v. t. & i. [D. inspannen.]
   To yoke or harness, as oxen to a vehicle. [South Africa]

Source : WordNet®

inspan
     v : attach a yoke or harness to; "inspan the draft animals"
         [ant: {outspan}]
     [also: {inspanning}, {inspanned}]