GC: n

S: BBC – https://bbc.in/2X8SFAV (last access: 19 February 2019); The Guardian – https://bit.ly/2T5feY4 (last access: 19 February 2019).

N: 1. hijack (v.): 1922, American English, perhaps from high(way) + jacker “one who holds up.” Originally “to rob (a bootlegger, smuggler, etc.) in transit;” sense of “seizing an aircraft in flight” is 1968 (also in 1961 variant skyjack), extended 1970s to any form of public transportation. Related: Hijacked; hijacking.
2. skyjack (v.): “to hijack an airplane,” 1961, apparently coined in New York “Mirror” headlines, from sky (n.) + second element of hijack (q.v.).
3. A person who illegally seizes an aircraft, ship, or vehicle while in transit and forces it to go to a different destination or uses it for their own purposes. Example: ‘negotiators began talks with the hijackers of the plane’.
A person who steals goods by seizing them in transit. Example: ‘a hijacker of arms shipments’.
A person who takes over an organization or activity and uses it for a different purpose. Example: ‘these activists are the real hijackers of the revolution’; ‘the hijackers of this government ignore all but their own agenda’.

S: 1 & 2. OED – https://bit.ly/2T80EyW (last access: 19 February 2019). 3. OD – https://bit.ly/2BG5tWg (last access: 19 February 2019).

OV : high-jacker

S: TERMIUM PLUS – https://bit.ly/2SIcMaG (last access: 19 February 2019)

SYN: sky-jacker

S: TERMIUM PLUS – https://bit.ly/2SIcMaG (last access: 19 February 2019)

CR: buccaneer, cracker, freebooter, letter of marque, piracy, piracy (2), pirate, privateer.