Maiden to speak, speak indistinctly (6)
I believe the answer is:
mutter
'speak indistinctly' is the definition.
(I've seen this before)
'maiden to speak' is the wordplay.
'maiden' becomes 'm' (cricket abbreviation).
'to speak' becomes 'utter' (synonyms).
'm'+'utter'='MUTTER'
(Other definitions for mutter that I've seen before include "Speak indistinctly or grumble" , "Mumble" , "Speak quietly and indistinctly" , "carp, > grouse and > beef" , "Low continuous sound" .)