Note queen occupying house, say (10)
I believe the answer is:
semiquaver
'note' is the definition.
(I know that semiquaver is a type of note)
'queen occupying house say' is the wordplay.
'queen' becomes 'qu' (abbreviation for queen).
'occupying' indicates putting letters inside (inserted letters occupy or enter the word).
'house' becomes 'semi' (short for semi-detached).
'say' becomes 'aver' (aver means to state or claim something).
'semi'+'aver'='semiaver'
'qu' put inside 'semiaver' is 'SEMIQUAVER'.
(Other definitions for semiquaver that I've seen before include "Musical note" , "A bit of music" , "Quarter of a crotchet" , "Very little music" .)