Trusty hen's first over place to hatch eggs (6)
I believe the answer is:
honest
'trusty' is the definition.
(associated in meaning)
'hen's first over place to hatch eggs' is the wordplay.
'first over' becomes 'o' (tst letter of 'over').
'place' indicates an anagram (I've seen 'placed' mean this (placing the letters)).
'to hatch eggs' becomes 't' (I can't explain this - if you can you should give a lot more credence to this answer).
'hens'+'o'='henso'
'henso' with letters rearranged gives 'hones'.
'hones'+'t'='HONEST'
Can you help me to learn more?
(Other definitions for honest that I've seen before include "Fair and free of deceit" , "Uncorrupt - open - genuine" , "Genuine; fair" , "Free of deceit, truthful by nature" , "Truthful and trustworthy" .)