Letter opener for post – share with another (6,2)
I believe the answer is:
'share with another' is the definition.
I can't tell whether this defines the answer.
'letter opener for post' is the wordplay.
'letter' becomes 'doubleu' (I've seen this before**).
'opener for' says to take the initial letters.
The initial letter of 'post' is 'p'.
Can you help me to learn more?
(Other definitions for double up that I've seen before include "sleep together" , "Bend forward in pain or laughter" , "Look pained" , "React to punch in gut" , "win?" .)