Summary

1911 Encyclopædia Britannica, Volume 8… (1911)

Latin decimalis, belonging to a tithe or tenth, and thus the “dismal days” are the unpleasant days connected with the extortion and oppression of exacting payment of tithes. According to the New English Dictionary, quoting Professor W. W. Skeat, “dismal” is derived, through an Anglo-Fr. dis mal, from the Lat. dies mali, evil or unpropitious days.
Source: Wikisource

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