Start to cut piece of wood, that's around a foot? (4)
I believe the answer is:
clog
'that's around a foot?' is the definition.
(clogs are shoes)
'start to cut piece of wood' is the wordplay.
'start to' indicates taking the first letters.
'piece of wood' becomes 'log'.
The initial letter of 'cut' is 'c'.
'c'+'log'='CLOG'
(Other definitions for clog that I've seen before include "Footwear - hamper" , "Wooden footwear" , "Wooden shoe; choke up" , "Block up - type of shoe" , "Congest" .)