beam: [OE] In Old English times the word bēam (like modern German baum) meant ‘tree’ – a signification preserved in tree-names such as hornbeam and whitebeam. But already before the year 1000 the extended meanings we are familiar with today – ‘piece of timber’ and ‘ray of light’ – had started to develop. Related forms in other Germanic languages (which include, as well as German baum, Dutch boom, from which English gets boom ‘spar’ [16]) suggest a West Germanic ancestor *bauma, but beyond that all is obscure. => boom
beam (n.)
Old English beam originally "living tree," but by late 10c. also "rafter, post, ship's timber," from Proto-Germanic *baumaz (cognates: Old Norse baðmr, Old Frisian bam "tree, gallows, beam," Middle Dutch boom, Old High German boum, German Baum "tree," Gothic bagms), perhaps from PIE verb root *bheue- "to grow" (see be). The shift from *-au- to -ea- is regular in Old English.
Meaning "ray of light" developed in Old English, probably because it was used by Bede to render Latin columna lucis, the Biblical "pillar of fire." Nautical sense of "one of the horizontal transverse timbers holding a ship together" is from early 13c., hence "greatest breadth of a ship," and slang broad in the beam "wide-hipped" (of persons). To be on the beam (1941) was originally an aviator's term for "to follow the course indicated by a radio beam."
beam (v.)
"emit rays of light," early 15c., from beam (n.) in the "ray of light" sense. Sense of "to smile radiantly" is from 1804; that of "to direct radio transmissions" is from 1927. Related: Beamed; beaming.
双语例句
1. The lighthouse beam was quite distinct in the gathering dusk.
灯塔的光束在渐浓的暮色中清晰可见。
来自柯林斯例句
2. He directed the tiny beam of light at the roof.
他把那一小束光对准了屋顶。
来自柯林斯例句
3. She froze when the beam of the flashlight struck her.