Clue: Stranger from France reorganised IKEA on return (8)
Answer: FREAKIER
Explanation: Definition: Stranger
A charade of FR ('France') plus EAKI, an anagram ('reorganised') of 'IKEA' plus ER, a reversal ('return') of RE ('on'). I really wanted the answer to be FREAKINO, a bizarre elementary particle, perhaps the constituent of Dark Matter.