late 14c., from Old French traf "crossbeam," from Latin trabem (nominative trabs) "beam," from PIE *treb- "dwelling" (see tavern).
"beam of light, light emitted in a given direction from a luminous body," early 14c., rai, from Old French rai (nominative rais) "ray (of the sun), spoke (of a wheel); gush, spurt," from Latin radius "ray, spoke, staff, rod" (see radius). Not common before 17c. [OED]; of the sun, usually in reference to heat (beam being preferred for light).
Ray is usually distinguished from beam, as indicating a smaller amount of light; in scientific use a beam is a collection of parallel rays. In ordinary language ray is the word usually employed when the reference is to the heat rather than the light of the sun .... [OED]
Science fiction's ray-gun is recorded by 1931 (in Amazing Stories; electric ray gun as an imaginary weapon is from 1924; death-ray gun from 1926 as a prop in a vaudeville act), but the Martians had a Heat-Ray weapon in "War of the Worlds" (1898).
1560s as an architectural feature of columns, "lower division of an entablature; part which rests immediately on the column and supports those portions of the structure above it;" extended 1660s to window parts, from Italian architrave, from Latin archi- "beginning, origin" (see archon) + Italian trave "beam," from Latin trabem (nominative trabs) "beam, timber" (from PIE root *treb- "dwelling," for which see tavern).
"timbers supporting a floor, etc.," early 14c. gist, giste, from Old French giste "beam supporting a bridge" (Modern French gîte), noun use of fem. past participle of gesir "to lie," from Latin iacēre "to lie, rest," related (via the notion of "to be thrown") to iacere "to throw" (from PIE root *ye- "to throw, impel"). The notion is of a wooden beam on which boards "lie down." The modern English vowel is a corruption.
1610s, "issue or spread in all directions from a point in rays or straight lines," from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius). Meaning "be radiant, give off rays (of light or heat)" is from 1640s. Related: Radiated; radiates; radiating.
"The fiery cross which in old times formed the rallying symbol in the Highlands of Scotland in any sudden emergency," Gaelic cranntara, cranntaraidh, also (by influence of crois "cross") croistara, croistaraidh, literally "the beam or cross of reproach," from crann "a beam, a shaft" (see crane (n.)) + tair "reproach, disgrace." "[S]o called because neglect of the symbol implied infamy" [Century Dictionary].
mid-14c., shoren, "to prop, support with or as if by a prop," from or related to shore (n.) "a prop, a support" (late 13c.); words of obscure etymology though widespread in Germanic (Middle Dutch schooren "to prop up, support;" Middle Low German schore "a barrier;" Old Norse skorða "piece of timber set up as a support"). Related: Shored; shoring.
The noun survives in technical senses, "post or beam for temporary support of something" (mid-15c.), especially an oblique timber to brace the side of a building or excavation.
"pivot on the end of a beam," c. 1400, from Old French gojon "pin, peg, spike" (13c.), perhaps somehow an altered sense of gudgeon (n.1).