Curiosity moving friend ultimately to DIY (6)
I believe the answer is:
oddity
'curiosity' is the definition.
(synonyms)
'moving friend ultimately to diy' is the wordplay.
'moving' is an anagram indicator.
'ultimately' indicates one should take the final letters.
The final letter of 'friend' is 'd'.
'd'+'to'+'diy'='dtodiy'
'dtodiy' is an anagram of 'ODDITY'.
(Other definitions for oddity that I've seen before include "David Bowie's Space ___" , "Toy did (anag.)" , "Curious item" , "Something strange or unusual" , "Peculiarity" .)