GC: n

S: The Guardian – https://bit.ly/2Q04IAQ (last access: 17 June 2018); WaPo – https://wapo.st/2rbQgXC (last access: 28 November 2018).

N: 1. – concertina (n): “portable, accordion-like musical instrument,” 1835, from concert + fem. ending -ina. Invented 1829 by English inventor Professor Charles Wheatstone (who also invented the stereoscope and the Wheatstone bridge).
– wire (n): Old English wir “metal drawn out into a fine thread,” from Proto-Germanic *wira- (source also of Old Norse viravirka “filigree work,” Swedish vira “to twist,” Old High German wiara “fine gold work”), from PIE root *wei- “to turn, twist, plait.”
A wire as marking the finish line of a racecourse is attested from 1883; hence the figurative down to the wire. Wire-puller in the political sense is 1848, American English, on the image of pulling the wires that work a puppet.
Concertina wire attested by 1917, so called from similarity to the musical instrument.
2. concertina: A coiled usually barbed wire that can be pushed together into a compact mass for transporting and extended for use as an obstacle.
3. concertina wire: Type of barbed wire or razor wire made from galvanised or stainless steel, manufactured in large coils which can be expanded like an accordion, characterised as an element of passive safety and used as an obstacle.

S: 1. OED – https://bit.ly/2E4NVG8; https://bit.ly/2BCCMtZ (last access: 17 June 2018). 2. TERMIUM PLUS – https://bit.ly/2BDNa4w (last access: 17 June 2018). 3. IATE – https://bit.ly/2BF3Mcl (last access: 17 June 2018).

SYN: concertina razor wire

S: wiremesh – https://bit.ly/2Rl29WH (last access: 17 June 2018)

CR: migration