Corrupt spy chief and others lead for example (4,5)
I believe the answer is:
base metal
'lead for example' is the definition.
(lead is an example of a base metal)
'corrupt spy chief and others' is the wordplay.
'corrupt' becomes 'base'.
'spy chief' becomes 'm' (M is the head of MI6 in the James Bond series).
'and others' becomes 'etal' ('et al.' can be a synonym of 'and others').
'base'+'m'+'etal'='BASE METAL'
(Other definitions for base metal that I've seen before include "For example, iron" , "Not being noble, it soon tarnishes" , "Lead for one" , "lead, say?" , "this isn't rare" .)