Hefin

In 1795 "Hefin" appeared in a manuscript by Iolo Morgannwg as part of an invented expression "Alban Hefin" (summer solstice). Hefin also appears as a Welsh word for "summer" in William Owen-Pughe's dictionary (1803). It is probably taken from the month name "Mehefin" (June) which literally means "midsummer" from the modern Welsh "Me-" (a prefix meaning mid) and "Haf" (summer) plus the suffix "-in."
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