Nostradamus's expensive instrument (5)
I believe the answer is:
strad
'expensive instrument' is the definition.
(I've seen this in another clue)
'nostradamus's' is the wordplay.
'STRAD' is hidden in amongst the letters.
But, I'm uncertain how this is indicated.
Can you help me to learn more?
(Other definitions for strad that I've seen before include "musical instrument" , "Noted violin" , "that Grappelli could have played" , "Top-quality violin (abbr.)" , "Valuable violin (abbrev.)" .)