Trace any random curve (8)
I believe the answer is:
catenary
'curve' is the definition.
(catenary is a kind of curve)
'trace any random' is the wordplay.
'random' indicates an anagram.
'trace'+'any'='traceany'
'traceany' anagrammed gives 'CATENARY'.
(Other definitions for catenary that I've seen before include "Curve formed by a hanging chain" , "it may be hanging in the air" .)