(Tenebrific comes from the Latin term tenebrae meaning “darkness”)
‘The swallow has the same mythical meaning as the cuckoo; it is the joyful herald of spring, emerging from the tenebrific winter.’
Angelo de Gubernatis
(“of powerful voice,” c.1600, from Stentor, legendary Greek herald in the Trojan War, whose voice (described in the “Iliad”) was as loud as 50 men. His name is from Greek stenein “groan, moan,” from PIE imitative root *(s)ten-, source of Old English þunor “thunder.” )
“I’ll tell you something else about which I’ve been lately thinking!” he bellowed in a suddenly stentorian voice. “I’ve been thinking about our beautiful country!” George Saunders
(From French fainéant, alteration of fait-néant (literally, does nothing) So a mistaken assumption about the derivation of the word turned the original French faignant (feigning) into faineant (does nothing), the present form. In French history, many kings have been called les rois fainéants as the real power was in the hands of mayors of the palace)