Welcome posh, kinky sex when drunk in a yard (11)
I believe the answer is:
hospitality
'welcome' is the definition.
(I know that hospitality is a type of welcome)
'posh kinky sex when drunk in a yard' is the wordplay.
'kinky' indicates anagramming the letters.
'sex' becomes 'it' (a common euphemism).
'when drunk in' becomes 'alit' (I can't explain this - if you can you should give a lot more credence to this answer).
'a yard' becomes 'y' (abbreviation).
'posh' anagrammed gives 'hosp'.
'hosp'+'it'+'alit'+'y'='HOSPITALITY'
Can you help me to learn more?
(Other definitions for hospitality that I've seen before include "Readiness to welcome guests" , "Cordial entertainment of guests" , "Kindness in welcoming guests" .)