1. a drop used for the clandestine exchange of intelligence information; - Example: "a dead drop avoids the need for an intelligence officer and a spy to be present at the same time"
WordNet (r) 3.0 (2006):
dead drop
n 1: a drop used for the clandestine exchange of intelligence
information; "a dead drop avoids the need for an
intelligence officer and a spy to be present at the same
time"