Generous cleaner's given one board (10)
I believe the answer is:
charitable
'generous' is the definition.
('charitable' is associated in meaning with 'generous')
'cleaner's given one board' is the wordplay.
'cleaner' becomes 'char' (charwoman is a type of cleaner).
'given' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'board' becomes 'table' ('table' can be a synonym of 'board').
'char'+'i'+'table'='CHARITABLE'
(Other definitions for charitable that I've seen before include "Benevolent" , "Inspired by the will to do good for others" , "Thoughtful" , "Big-hearted" , "Kindly, given to good works" .)