Brief about pee containing metallic element (8)
I believe the answer is:
telluric
'brief' is the definition.
Although both the answer and definition are adjectives, I don't see how one could define the other.
'about pee containing metallic element' is the wordplay.
I cannot quite understand how this works, but
'about' could be 'c' (circa) and 'c' is present in the answer.
'element' could be 'ell' (ell is a kind of element) and 'ell' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for telluric that I've seen before include "originating in the earth?" , "Of the earth or soil" .)