Countless men run Bude, surprisingly (10)
I believe the answer is:
unnumbered
'countless' is the definition.
(I know that countless can be written as unnumbered)
'men run bude surprisingly' is the wordplay.
'surprisingly' indicates anagramming the letters (a surprising ordering of the letters).
'men'+'run'+'bude'='menrunbude'
'menrunbude' anagrammed gives 'UNNUMBERED'.
(Other definitions for unnumbered that I've seen before include "clues in this puzzle are not like this" , "Countless" .)