Very happy to secure copper or another metal (7)
I believe the answer is:
mercury
'another metal' is the definition.
'mercury' can be an answer for 'metal' (mercury is a kind of metal). I'm not certain of the 'another' bit.
'very happy to secure copper' is the wordplay.
'very happy' becomes 'merry' (I am not sure about the 'very' bit.).
'to secure' indicates putting letters inside (inserted letters are secured inside).
'copper' becomes 'Cu' (Cu is the chemical symbol for copper).
'merry' placed around 'cu' is 'MERCURY'.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for mercury that I've seen before include "Messenger in Roman mythology" , "Element, symbol Hg" , "one in distant orbit?" , "In Roman myth, the messenger of the gods" , "Metal in thermometer or barometer" .)