Extremely, informally (5)
(Other definitions for ultra that I've seen before include "Project started at Bletchley Park in 1939 to break the Enigma code" , "Above, beyond, super" , "Violet's predecessor" , "Over the top" , "Political extremist" .)
'extremely informally' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for way that I've seen before include "Manner; road" , "Method; route" , "Street" , "'Manner, mode (3)'" , "Path" .)