Made English chemical company second, having fished around (10)

'made english' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?

'chemical company second having fished around' is the wordplay.
'chemical company' becomes 'ici' (former company Imperial Chemical Industries).
'second' becomes 's' (common abbreviation).
'having' says to put letters next to each other.
'fished' becomes 'angled' (angling is a kind of fishing).
'around' means one lot of letters goes inside another.
'ici'+'s'='icis'
'icis' placed into 'angled' is 'ANGLICISED'.

Can you help me to learn more?