Noticed about English - everything is a defence (7)

I believe the answer is:

seawall

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'a defence' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?

'noticed about english everything' is the wordplay.
'noticed' becomes 'saw' (I've seen this in another clue).
'about' indicates putting letters inside.
'english' becomes 'E' (abbreviation).
'everything' becomes 'all' (all things).
'saw' going around 'e' is 'seaw'.
'seaw'+'all'='SEAWALL'

'is' is the link.

Can you help me to learn more?

(Another definition for seawall that I've seen is " sea defence".)

I've seen this clue in The Daily Express.

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