Amalda is a female name of uncertain origin. I’ve seen numerous sites list it as deriving from a Germanic origin, likely from Germanic element *amal meaning “work, labor”, and could possibly be considered as a variant of Amalia. Amalda is also the name of a genus of sea snails in the Olividae family (pictured above).
There seems to be a character called Amalda in a book, Famous Assassinations of History, from the Time of Julius Caesar Down to the Present by Dennis O’Sullivan. It was published in 1882 and I couldn’t find much information on it, although I’ve posted the link below. Another Amalda I’ve found is mentioned during one of the Crusades in 1570, when Ottoman forces conquered the island of Cyprus (under Venetian rule) and killed many of the troops and townspeople despite promises of their safety if they surrendered.Those that survived were enslaved and sent to Turkey for slavery but one of them, Amalda de Rocas, chose to die instead, setting fire to the ship she and the other captors were on and blowing it up. I don’t know if that particular story is true- if they all died on the ship, than how could anyone know who blew it up?
Origin: possibly Proto-Germanic