Fired up over the ultimate in a bucket list (4)
I believe the answer is:
'list' is the definition.
(both can mean to lean)
'fired up over the ultimate in a bucket' is the wordplay.
'fired up' becomes 'lit' (I've seen this in another clue).
'over' says the letters should be written backwards.
'the ultimate in' suggests the final letters.
The last letter of 'bucket' is 't'.
'lit' in reverse letter order is 'til'.
(Other definitions for tilt that I've seen before include "Inclination, joust" , "Move into a sloping position, say a lance" , "Thrust with lance, like Don Quixote at windmills" , "Slope; joust" , "Incline, slant" .)