Natural spirit topped any speed (5)
I believe the answer is:
nymph
'natural spirit' is the definition.
'nymph' can be an answer for 'spirit' (I've seen this before). I am unsure of the 'natural' bit.
'topped any speed' is the wordplay.
'topped' means to remove the first letter (to top something is to remove its top).
'speed' becomes 'mph' (abbreviation for miles per hour).
'any' with its initial letter removed is 'ny'.
'ny'+'mph'='NYMPH'
Can you help me to learn more?
(Other definitions for nymph that I've seen before include "Goddess - larval form" , "Demigoddess" , "Beautiful young maiden" , "Immature form of an insect" , "Larva of aquatic insect" .)