blanket jam
— Verb
– English
～ jam a broad spectrum of frequencies to affect all communications in the area except for directional antenna communications
Buteo jamaicensis
— Noun
– English
～ dark brown American hawk species having a reddish-brown tail
barrage jamming
— Noun
– English
～ electronic jamming over a wide range of frequencies simultaneously
Bromus japonicus
— Noun
– English
～ grass of Mediterranean and temperate Asia
bell jar
— Noun
– English
～ a bell-shaped glass cover used to protect and display delicate objects or to cover scientific apparatus or to contain gases