Goblin (6)
'goblin' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gnome that I've seen before include "Little old elf" , "Underground dwarf" , "little chap fishing in the garden" , "Little old man of legend" , "Fairytale dwarf, often in garden" .)
(Other definitions for spirit that I've seen before include "Wraith" , "Possibly a rum" , "Courage, energy" , "Ghost or vigor" , "Ghost - pluck" .)