Quicksilver mostly lies all over the place? (5)
I believe the answer is:
agile
'quicksilver mostly lies all over the place?' is the definition.
I can't tell whether this definition defines the answer.
'quicksilver mostly lies all over the place?' is the wordplay.
'quicksilver' becomes 'ag' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mostly' means to remove the last letter (most but not all of the word).
'all over the place?' indicates anagramming the letters.
'lies' with its final letter taken away is 'lie'.
'lie' with letters rearranged gives 'ile'.
'ag'+'ile'='AGILE'
Can you help me to learn more?
(Other definitions for agile that I've seen before include "Quick to move" , "Mentally acute" , "Physically quick and nimble" , "Dexterous" , "Lithely moving" .)