Notices day film school's leaderless (7)

I believe the answer is:

detects

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'notices' is the definition.
('detect' can be a synonym of 'notice')

'day film school's leaderless' is the wordplay.
'day film' becomes 'det' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'school's' becomes 'sect's' (sect can mean a faction or school of thought).
'leaderless' means to remove the first letter.
'sects' with its initial letter removed is 'ects'.
'det'+'ects'='DETECTS'

Can you help me to learn more?

(Other definitions for detects that I've seen before include "Discovers, determines the existence" , "notices" , "Discerns" .)

I've seen this clue in The Times.

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