Crossword Genius

Ultimately, wad super fat (8)

Ross

I believe the answer is:

'fat' is the definition.
(dripping is a kind of fat)

'ultimately wad super' is the wordplay.
'ultimately' says to take the final letters.
'super' becomes 'ripping' (old-fashioned informal term for excellent).
The final letter of 'wad' is 'd'.
'd'+'ripping'='DRIPPING'

(Other definitions for dripping that I've seen before include "Very wet; fat from roast", "Saturated", "tap needing washer?", "sweaty", "F [FAT]".)

I've seen this clue in The Guardian.