Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
flat-footed is an adjective meaning "with feet flat on the ground; not tiptoe". It carries 4 recorded senses.
with feet flat on the ground; not tiptoe
unprepared and unable to react quickly
“the new product caught their competitors flat-footed”
having broad flat feet that usually turn outward
“a slow flat-footed walk”
Definitions, synonyms and semantic relations for flat-footed come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.