A clear field (5)
'a clear' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for plain that I've seen before include "Simple - flatland" , "Straightforward" , "lament" , "Undecorated; clear" , "Clear, candid" .)
'field?' is the definition.
(lea can mean a meadow or field of grass)
'a clear' is the wordplay.
'LEA' is hidden in amongst the letters.
But, I'm uncertain how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for lea that I've seen before include "Land growing grass" , "grazing area" , "authority for teachers" , "Open pasture" , "Open area of grassy or arable land" .)