Definify.com
Webster 1913 Edition
Headway
Head′wayˊ
(-wûrkˊ)
, Noun.
1.
The progress made by a ship in motion; hence, progress or success of any kind.
2.
(Arch.)
Clear space under an arch, girder, and the like, sufficient to allow of easy passing underneath; clearance; headroom.
Webster 1828 Edition
Headway
HEADWAY
,Noun.