glower (v.)youdaoicibaDictYouDict[glower 词源字典]
mid-14c., "to shine;" c. 1500, "to stare with wide eyes," perhaps from a Scandinavian source (compare Norwegian dialectal glora "to glow, gleam; stare"), or related to Middle Dutch gluren "to leer;" in either case from Proto-Germanic *glo- (see glow (v.)), root of Old English glowan "to glow," which influenced the spelling of this word. Meaning "to look angrily, look intently and threateningly, scowl" is from 18c. Related: Glowered; glowering. As a noun, 1715, "an angry or threatening stare," from the verb.[glower etymology, glower origin, 英语词源]
thunder (v.)youdaoicibaDictYouDict
13c., from Old English þunrian, from the source of thunder (n.). Figurative sense of "to speak loudly, threateningly, or bombastically" is recorded from mid-14c. Related: Thundered; thundering. Compare Dutch donderen, German donnern.