From the waves in the front of the ship, getting sick (7)

'from' is the definition.
I can't judge whether this defines the answer.

'waves in the front of the ship getting sick' is the wordplay.
'waves in' becomes 'bow' (I can't justify this - if you can you should believe this answer much more).
'the front of' says to take the initial letters (the letter at the front of the word).
'getting' indicates putting letters inside.
'sick' becomes 'ill' (similar in meaning).
The initial letter of 'ship' is 's'.
'bow'+'s'='bows'
'bows' enclosing 'ill' is 'BILLOWS'.

'the' acts as a link.

Can you help me to learn more?