In order to explain ‘wire’ it is necessary to look first at modern slang. Initially found in the 1950’s, the term ‘wired’ when used to mean ‘nervous, tense’ is actually from much earlier. When we read of the affluent of old wearing gold cloth, in truth this is describing very fine gold wire woven into the cloth. It is easy to see how this would make the resulting garment heavier and more rigid, just as the modern sense ‘wired’ would suggest in slang and as also in the producing certain undergarments.
Tracing the etymology of this use of ‘wire’ we find Old German wiara meaning ‘fine gold work’, Old Norse viravirka ‘filigree work’, Swedish via ‘to twist’, Latin viere ‘to twist or bend’, and Old Irish fiar and Old Welsh gwyr both meaning ‘bent, crooked’. All these can be traced to a Celtic viriae and to the Proto-Germanic wira, both used in connection with producing bracelets. Many will have seen ornaments worn by Celts known as torcs, ostensibly twisted length of metal to produce a bangle-like decoration for the wrist or sometimes as a necklace.
All these words can be traced to the Proto-Indo-European wei meaning ‘to turn’, ‘to twist’, or even ‘plait’ and thus the original sense was to describe the process of drawing out the metal in finer diameters. This is exactly the same process which produces what we would recognise as ‘wire’ today.