Assumes they're Spanish (4)

I believe the answer is:

dons

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'assumes' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for dons that I've seen before include "University teachers - Mafia bosses" , "Academics" , "British university teachers and Spanish noblemen" , "Puts on -- lecturers" , "Assumes" .)

I've seen this clue in The Globe and Mail.

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