Time wasted behind prison camp formation (10)
I believe the answer is:
stalagmite
'formation' is the definition.
The answer and definition can be both natural objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'time wasted behind prison camp' is the wordplay.
'wasted' indicates an anagram.
'behind' means one lot of letters go next to another.
'prison camp' becomes 'stalag' (I've seen this before).
'time' anagrammed gives 'mite'.
'mite' after 'stalag' is 'STALAGMITE'.
Can you help me to learn more?
(Other definitions for stalagmite that I've seen before include "something on floor of underground passage" , "Upward-rising cave deposit" , "Cave floor growth" , "A mound of calcium carbonate" , "Pillar of the underground" .)