Unable to pitch? (4)
I believe the answer is:
cant
I believe this is a double definition.
'unable to' is the first definition.
'pitch?' is the second definition.
('cant' can be a synonym of 'pitch')
(Other definitions for cant that I've seen before include "Stock phrases made nonsensical by endless repetition" , "Not able to" , "tilt" , "Pious platitudes -- jargon" , "Slope; thieves' talk" .)