Odd trinkets containing uranium (7)
I believe the answer is:
curious
'odd' is the definition.
(I know that odd can be written as curious)
'trinkets containing uranium' is the wordplay.
'trinkets' becomes 'curios' (I can't justify this - if you can you should give a lot more credence to this answer).
'containing' means one lot of letters goes inside another.
'uranium' becomes 'U' (U is the chemical symbol for uranium).
'curios' enclosing 'u' is 'CURIOUS'.
Can you help me to learn more?
(Other definitions for curious that I've seen before include "Odd, peculiar" , "Eager to learn something" , "Eager to learn, strange" , "Odd or eager to know" , "Eager to know; strange" .)