Webster's Revised Unabridged Dictionary · 1913

Flat-footed

Flat-footed , adjective

1.
Having a flat foot, with little or no arch of the instep; suffering from fallen arches.
2.
Firm-footed; determined. [Slang, United States]
3.
clumsy; amateurish; pedestrian; unimaginative; plodding; as, flatfooted prose.
4.
Without reservation; without evasion or compromise; firm; as, a flat-footed refusal; a flatfooted denial.
5.
With feet flat on the ground; not tiptoe.
6.
Unprepared and unable to react quickly; as, the new product caught their competitors flat-footed.
Collocations (1)
To catch (one) flatfooted , to catch (a person) unprepared; to catch (a person) by surprise.