Cooker called “stove”, ultimately (5)
I believe the answer is:
range
'cooker' is the definition.
(I know that cooker can be written as range)
'called stove ultimately' is the wordplay.
'called' becomes 'rang' (called on the phone).
'ultimately' indicates one should take the final letters.
The last letter of 'stove' is 'e'.
'rang'+'e'='RANGE'
(Other definitions for range that I've seen before include "Series of connected mountains" , "Ramble" , "Full choice of clothes" , "Cowboy song 'Home on the . . . . .'" , "Old-style cooking stove" .)