-grade
1.
a combining form meaning “walking, moving,” in the manner or by the means specified by the initial element:
plantigrade.
Origin
<
Latin
-gradus,
combining form representing
gradus
step or
gradī
to walk. See
grade
,
gradient
British Dictionary definitions for
-grade
-grade
combining form
1.
indicating a kind or manner of movement or progression:
plantigrade,
retrograde
Word Origin
via French from Latin
-gradus,
from
gradus
a step, from
gradī
to walk