They are found growing next to a trunk (5)
I believe the answer is:
tusks
'they' is the definition.
Both the answer and definition are plural nouns.
Maybe you can see a link between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for tusks that I've seen before include "Elephant's long teeth" , "tough projections" , "Some ivory" , "Elephant's dentines" , "feature on Morse" .)