What is the origin of lacuna?
In Latin lacūna means “ditch, pit, gap, deficiency, hole, hole where water collects.” Modern French lagune “lagoon,” Italian laguna “lagoon,” and Spanish laguna “lagoon, gap” are obvious developments from lacūna. Lacūna in turn is a derivative of lacus “basin, tub, cistern, pond, lake,” the source (through Old French) of English lake. Latin lacus is also related to Scots Gaelic and Irish loch. Lacuna entered English in the 17th century.