Obtains a variety of solid defence (7)
I believe the answer is:
bastion
'solid defence' is the definition.
'bastion' can be an answer for 'defence' (bastion is a kind of defence). I'm not certain of the 'solid' bit.
'obtains a variety' is the wordplay.
'a variety' indicates an anagram.
'obtains' anagrammed gives 'BASTION'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for bastion that I've seen before include "'Stronghold, citadel (7)'" , "Obtains (anag.)" , "Projecting part of a fortification" , "Stronghold, fortification" , "Fortified place near hostile territory" .)