Mosquito, say, in open area dancing around lady's head (9)
I believe the answer is:
aeroplane
'mosquito say' is the definition.
(I know that Mosquito is a type of military airplane with 2 engines)
'open area dancing around lady's head' is the wordplay.
'dancing' indicates an anagram.
'around' is an insertion indicator.
'head' says to take the initial letters.
The initial letter of 'lady' is 'l'.
'open'+'area'='openarea'
'openarea' is an anagram of 'aeropane'.
'aeropane' going around 'l' is 'AEROPLANE'.
'in' acts as a link.
(Other definitions for aeroplane that I've seen before include "Flying machine" , "crate?" , "Flier" , "Eg, jumbo jet" , "Lancaster?" .)