D defs.my
Entry 2 senses Webster, 1913

Headway

/(-wûrk`)/ · Head·way · IPA /ˈhɛdweɪ/
01 n. The progress made by a ship in motion; hence, progress or success of any kind.
  1. 1.
    The progress made by a ship in motion; hence, progress or success of any kind.
  2. 2.
    Clear space under an arch, girder, and the like, sufficient to allow of easy passing underneath; clearance; headroom.(Arch.)