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Old English weall "rampart" (natural as well as man-made), also "defensive fortification around a city, side of a building, interior partition," an Anglo-Frisian and Saxon borrowing (cf. Old Saxon, Old Frisian, Middle Low German, Middle Dutch wal) from Latin vallum "wall, rampart, row or line of stakes," apparently a collective form of vallus "stake." Swedish vall, Danish val are from Low German.
In this case, English uses one word where many languages have two, e.g. German Mauer "outer wall of a town, fortress, etc.," used also in reference to the former Berlin Wall, and wand "partition wall within a building" (cf. the distinction, not always rigorously kept, in Italian muro/parete, Irish mur/fraig, Lithuanian muras/siena, etc.).
Phrase up the wall "angry, crazy" is from 1951; off the wall "unorthodox, unconventional" is recorded from 1966, American English student slang. Wall-to-wall (adj.) recorded 1953, of carpeting; metaphoric use (usually disparaging) is from 1967.
"to enclose in a wall," late Old English *weallian, from the source of wall (n.). Related: Walled; walling.
An investing part enclosing a cavity, chamber, or other anatomical unit.
To explain something carefully and gradually; learn something by going slowly through the steps: I'll walk you through it one more time; you nearly have it right
[mid-1800s+ Theater; fr the practice of learning a role partly by moving about onstage without speaking the lines]
Cities were surrounded by walls, as distinguished from "unwalled villages" (Ezek. 38:11; Lev. 25:29-34). They were made thick and strong (Num. 13:28; Deut. 3:5). Among the Jews walls were built of stone, some of those in the temple being of great size (1 Kings 6:7; 7:9-12; 20:30; Mark 13:1, 2). The term is used metaphorically of security and safety (Isa. 26:1; 60:18; Rev. 21:12-20). (See FENCE.)