Mistranslated Latin, being unclear (10)
I believe the answer is:
intangible
'unclear' is the definition.
(I've seen this before)
'mistranslated latin being' is the wordplay.
'mistranslated' indicates an anagram.
'latin'+'being'='latinbeing'
'latinbeing' with letters rearranged gives 'INTANGIBLE'.
(Other definitions for intangible that I've seen before include "Elusive" , "unclear" , "Abstract - hard to grasp" .)