What workers collect almost swamps court (6)
I believe the answer is:
nectar
'what workers collect' is the definition.
(as in worker bees)
'almost swamps court' is the wordplay.
'almost' becomes 'near' (I've seen this in another clue).
'swamps' indicates putting letters inside (inserted letters are covered up or swamped).
'court' becomes 'ct' (abbreviation used in road names).
'near' placed around 'ct' is 'NECTAR'.
(Other definitions for nectar that I've seen before include "Source of honey" , "Sweet plant secretion" , "Sugary stuff in plants to attract insects" , "That's sweet" , "Delicious drink for Cretan" .)