Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
quā̆drŭpĕdus (quā̆drĭpĕdus, Front. ad M. Anton. Or. 1), a, um, adj. [quadrupes], going on four feet, galloping (postAug.): quadrupedo gradu repentes, on all fours, Amm. 14, 2, 2: quadripedo cursu, on a gallop, Front. 1, 1.
Absol.: quadrupedo currere, to gallop, Front. Ep. ad M. Caes. 2, 1.