Word Study
waywiser
CIDE DICTIONARY
waywiser, n. [Cf. G. wegweiser a waymark, a guide; weg way + weisen to show, direct.].
An instrument for measuring the distance which one has traveled on the road; an odometer, pedometer, or perambulator. [1913 Webster]
"The waywiser to a coach, exactly measuring the miles, and showing them by an index."
[1913 Webster]
For further exploring for "waywiser" in Webster Dictionary Online
