Dinosaur held up by pterodactyl is so fierce (6)
I believe the answer is:
fossil
'dinosaur' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'held up by pterodactyl is so fierce' is the wordplay.
'up by' shows that the letters should be reversed in order.
'held' says the answer is hidden in the clue.
'lissof' is hidden within 'pterodactyl is so fierce'.
'lissof' written backwards gives 'FOSSIL'.
Can you help me to learn more?
(Other definitions for fossil that I've seen before include "Fuddy-duddy" , "One petrified" , "Animal remnant preserved in rock" , "Remains or impression of a prehistoric plant or animal" , "Petrified relic" .)