With reference to (2,3)
'with reference to' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for apropos that I've seen before include "suitably" , "As regards" , "Regarding" , "Suitable or relevant" , "In respect of" .)
'with reference to' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for as for that I've seen before include "With regard to" , "With reference to" .)