Crossword Genius

Blue, having cut short dive — lacking this? (8)

Ross

I believe the answer is:

aqualung

I'm a little stuck... Click here to teach me more about this clue!

'lacking this?' is the definition.
The definition suggests a singular noun which matches the answer.

'blue having cut short dive' is the wordplay.
'blue' becomes 'aqua' (aqua is a kind of blue).
'having' means one lot of letters go next to another.
'cut short dive' becomes 'lung' (I can't explain this - if you can you should give a lot more credence to this answer).
'aqua'+'lung'='AQUALUNG'

Can you help me to learn more?

(Other definitions for aqualung that I've seen before include "Diving apparatus" , "Diving equipment with cylinders of compressed air" , "Diver's breathing apparatus" , "Aid for diver" , "Underwater breathing apparatus" .)

I've seen this clue in The Times.
Want a hint initially instead of a full solution? Install my app