Occasionally unsafe to go round room that houses engine (7)
I believe the answer is:
nacelle
'houses engine' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'occasionally unsafe to go round room' is the wordplay.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'to go round' is an insertion indicator.
'room' becomes 'cell' (cell is a kind of room).
The alternate letters of 'unsafe' are 'nae'.
'nae' placed around 'cell' is 'NACELLE'.
'that' is the link.
Can you help me to learn more?
(Other definitions for nacelle that I've seen before include "Aircraft engine casing" , "part of the aeroplane" , "Enclosure for an aircraft engine" , "Aircraft engine fairing" , "Streamlined cover for an aircraft engine" .)