Donkey on international motorway slow to merge with locals (10)
I believe the answer is:
assimilate
'merge with locals' is the definition.
I can't judge whether this definition defines the answer.
'donkey on international motorway slow' is the wordplay.
'donkey' becomes 'ass' (ass is a term for a donkey).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'international' becomes 'i' (abbreviation eg in IMF).
'motorway' becomes 'MI' (resembles Ml, English motorway).
'slow' becomes 'late' (I've seen this in other clues).
'ass'+'i'+'mi'+'late'='ASSIMILATE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for assimilate that I've seen before include "Absorb and digest (food)" , "thoroughly understood" , "Become part of the prevailing culture" , "Take in and understand" , "pick up" .)