Divers love working in Lesotho (5)
I believe the answer is:
loons
'divers' is the definition.
('loon' can be a synonym of 'diver')
'love working in lesotho' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'working' becomes 'on' (on can mean working or activated).
'in' means one lot of letters goes inside another.
'lesotho' becomes 'ls' (I can't explain this - if you can you should believe this answer much more).
'o'+'on'='oon'
'oon' put within 'ls' is 'LOONS'.
Can you help me to learn more?
(Other definitions for loons that I've seen before include "Casual bags" , "Birds" , "of similar type to 2 down [NUMBSKULL]?" .)