Hole up around yard with rocks when eavesdropping - this is basic (9)
I believe the answer is:
hydroxide
'eavesdropping this is basic' is the definition.
The definition suggests a singular noun which matches the answer.
'hole up around yard with rocks' is the wordplay.
'hole up' becomes 'hide' (to hole up somewhere is to hide there).
'around' indicates putting letters inside.
'yard' becomes 'yd' (abbreviation).
'with' is a charade indicator (letters next to each other).
'rocks' becomes 'rox' (I can't explain this - if you can you should believe this answer much more).
'yd'+'rox'='ydrox'
'hide' enclosing 'ydrox' is 'HYDROXIDE'.
'when' acts as a link.
Can you help me to learn more?
(Other definitions for hydroxide that I've seen before include "Hired doxy to make compound of hydrogen and oxygen" , "Chemical compound, OH" .)