Gains second online at university in African city (8)

'gains' is the definition.
Although both the answer and definition are plural nouns, I don't understand how one could define the other.

'second online at university in african city' is the wordplay.
'second online' becomes 'ls' (I can't justify this - if you can you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'university' becomes 'U' (abbreviation for university).
'in' means one lot of letters goes inside another.
'african city' becomes 'accra' (capital of Ghana).
'u' going within 'accra' is 'accrua'.
'ls' after 'accrua' is 'ACCRUALS'.

Can you help me to learn more?