【医】 lacuna
antrum; cavity
【医】 cava; cavern; caverna; cavitas; cavitat; cavity; cavum; celio-; chamber
coel-; coelio-; lumen; lumina; space; spatia; spatium
crack; crevice; gap; interval; opportunity; rift
【化】 opening
【医】 gap; space; spatia; spatium; split