It's used for pumping reggae with sun out (6,3)

I believe the answer is:

grease gun

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

'it's used for pumping' is the definition.
I can't tell whether this defines the answer.

'reggae with sun out' is the wordplay.
'with' means one lot of letters go next to another.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'reggae'+'sun'='reggaesun'
'reggaesun' is an anagram of 'GREASE-GUN'.

Can you help me to learn more?

(Other definitions for grease gun that I've seen before include "Lubricating pump" , "Lubricant applicator" , "Lubricant applier" , "Lubricating device" .)

I've seen this clue in The Everyman puzzle in The Observer.

Want a hint initially instead of a full solution? Install my app