Are they people who speak for Dorothy Leigh? (6)
I believe the answer is:
sayers
'are they people who' is the definition.
The definition suggests a singular noun which matches the answer.
'speak for dorothy leigh?' is the wordplay.
'speak' becomes 'say' (I've seen this in another clue).
'for' says to put letters next to each other.
'dorothy leigh?' becomes 'ers' (I can't justify this - if you can you should give a lot more credence to this answer).
'say'+'ers'='SAYERS'
Can you help me to learn more?
(Other definitions for sayers that I've seen before include "Dorothy L. --, novelist" , "detective story writer" , "They claim" , "Peig and Dorothy L." , "she wrote mysteries" .)