1. The lid of a pitcher-form leaf, or of the spore-vessel of a moss; the plate which closes the orifice of a shell; the apparatus which protects the gills of fishes.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• iperculum,
• kperculum,
• lperculum,
• pperculum,
• 0perculum,
• 9perculum,
• ooerculum,
• operculim,
• opperculum,
• oplerculum,
• oprculum,
• opecrulum,
• opercullum,
• opurculum,
• opersulum,
• spechulum,
• specuilum,
• Ferculum,
• opusclum,
• opuscuulum

• operculated,
• operculate.

The adjective form of the word "operculum" is "opercular".