noun
double bottom; false bottom; double sole; double hull
Refers to a second, often hidden, bottom layer in containers, ships, shoes, etc. Used in contexts like smuggling, insulation, or reinforcement.
そのトランクには二重底があって、密輸品が隠されていた。
The trunk had a false bottom where contraband was hidden.
この船は二重底構造で、安全性が高い。
This ship has a double-bottom structure, making it very safe.