A pair of students and old workers fill dry beds here (9)
I believe the answer is:
allotment
'beds here' is the definition.
(beds for growing plants in a rented plot)
'a pair of students and old workers fill dry' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'of' could be 'o' and 'o' is found within the answer.
'students' could be 'll' (two abbreviations for learner) and 'll' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for allotment that I've seen before include "grant?" , "Where vegetables may be produced" , "Rented garden plot" , "growing area?" , "Vegetable plot" .)