Meeting marines at sea (7)

I believe the answer is:

seminar

'meeting' is the definition.
(seminar is a kind of meeting)

'marines at sea' is the wordplay.
'at sea' is an anagram indicator.
'marines' is an anagram of 'SEMINAR'.

(Other definitions for seminar that I've seen before include "Student discussion group - remains (anag)" , "Study group on specific subject" , "Marines (anag.)" , "Training meeting" , "Working meeting in College" .)

I've seen this clue in The Telegraph.

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