Suddenly mention glimpse of Lune going into Lancaster (5)
I believe the answer is:
blurt
'suddenly mention' is the definition.
'blurt' can be an answer for 'mention' (thesaurus). I am not sure about the 'suddenly' bit.
'glimpse of lune going into lancaster' is the wordplay.
'glimpse of lune going' becomes 'l' (I can't justify this - if you can you should believe this answer much more).
'into' means one lot of letters goes inside another.
'lancaster' becomes 'burt' (I've seen this in another clue).
'l' put into 'burt' is 'BLURT'.
Can you help me to learn more?
(Other definitions for blurt that I've seen before include "Utter suddenly" , "Utter impulsively" .)