Ventilates the mid-part of the body in dirigibles (8)

'dirigibles' is the definition.
('airship' can be a synonym of 'dirigible')

'ventilates the mid-part of the body in' is the wordplay.
'ventilates' becomes 'airs' ('air' can be a synonym of 'ventilate').
'the mid' indicates the central letters.
'part' becomes 'bit' (both mean a piece of something).
'of the body' becomes 'hps' (I can't justify this - if you can you should give a lot more credence to this answer).
'in' means one lot of letters goes inside another.
The central letter of 'bit' is 'i'.
'i' going within 'hps' is 'hips'.
'airs'+'hips'='AIRSHIPS'

Can you help me to learn more?