Characteristic spirit of English chap lacking master’s degree (5)

I believe the answer is:

ethos

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

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for ethos that I've seen before include "Distinctive principles of an era, group, etc" , "Distinctive group spirit" , "Distinctive spirit - character" , "Spirit (of, eg, an age)" , "The distinctive spirit of a culture or an era" .)

I've seen this clue in The Times.

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