flat-footed

• POS: Adjective
• HYPHEN: flat-foot=ed

CIDE DICTIONARY

flat-footed, a. 

•  Having a flat foot, with little or no arch of the instep; suffering from fallen arches.  [1913 Webster]
•  Firm-footed; determined.  [1913 Webster]
•  clumsy; amateurish; pedestrian; unimaginative; plodding; as, flatfooted prose.  [PJC]
•  Without reservation; without evasion or compromise; firm; as, a flat-footed refusal; a flatfooted denial.  [PJC]
•  With feet flat on the ground; not tiptoe.  [WordNet 1.5]
•  Unprepared and unable to react quickly; as, the new product caught their competitors flat-footed.  [WordNet 1.5]

To catch (one) flatfooted to catch (a person) unprepared; to catch (a person) by surprise.

OXFORD DICTIONARY

flat-footed, adj.
1 having flat feet.
2 colloq. downright, positive.
3 colloq. unprepared; off guard (was caught flat-footed).

Derivative

flat-footedly adv. flat-footedness n.