Recklessly dived with nothing on, being bare (6)
I believe the answer is:
devoid
'being bare' is the definition.
(thesaurus)
'recklessly dived with nothing' is the wordplay.
'recklessly' indicates anagramming the letters (I've seen this in other clues).
'with' means one lot of letters goes inside another.
'nothing' becomes 'o' (O resembles 0).
'dived' with letters rearranged gives 'devid'.
'devid' enclosing 'o' is 'DEVOID'.
'on' acts as a link.
(Other definitions for devoid that I've seen before include "Entirely free (of)" , "Bereft" , "Empty - do dive (anag)" , "Free (of something)" , "Empty or free from" .)