Start to undress in land by middle of Wimbledon Common (5)
I believe the answer is:
usual
'common' is the definition.
('usual' can be similar in meaning to 'common')
'start to undress in land by middle of wimbledon' is the wordplay.
'start to' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'land' becomes 'usa' (USA is an example).
'by' says to put letters next to each other.
'middle of' says to take the centre.
The middle of 'wimbledon' is 'l'.
The first letter of 'undress' is 'u'.
'u' placed inside 'usa' is 'usua'.
'usua'+'l'='USUAL'
(Other definitions for usual that I've seen before include "regarding customs?" , "Standard" , "Typically done" , "Normal, customary" , "Stock" .)