It's delivered along the ground air ducts, yet to be processed (5-6)
I believe the answer is:
daisy-cutter
'it's delivered along the ground' is the definition.
(delivery that goes along the ground in cricket)
'air ducts yet to be processed' is the wordplay.
'to be processed' indicates an anagram.
'air'+'ducts'+'yet'='airductsyet'
'airductsyet' anagrammed gives 'DAISY-CUTTER'.
(Other definitions for daisy-cutter that I've seen before include "Low-pitched ball" , "Tidy curates (anag.)" , "Ball that skims along the ground" , "Cricket delivery skimming along the ground" , "Ball bowled that shoots along the ground" .)