Foreign invader, colonist with current information (7)
I believe the answer is:
antigen
'foreign invader' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'colonist with current information' is the wordplay.
'colonist' becomes 'ant' (I've seen this before).
'with' means one lot of letters go next to another.
'current' becomes 'i' (symbol for electric current).
'information' becomes 'gen' (gen can informally mean information).
'ant'+'i'+'gen'='ANTIGEN'
Can you help me to learn more?
(Other definitions for antigen that I've seen before include "toxin" , "It stimulates immune responses - tag nine (anag)" , "Immunity-booster" , "Substance inducing an immune response" , "Biological substance" .)