Word origin
 [1940–45; 
R(
esearch) 
D(
epartment) (
E)
x(
plosive), referring to such a department in Woolwich, England
]This word is first recorded in the period 1940–45. Other words that entered Englishat around the same time include: blockbuster, debrief, sealant, set-aside, snorkel