An adjective meaning “empty” attested only as an element in the Ilkorin name Mablosgen (Ety/MAP). As suggested by Helge Fauskanger, it might be a combination of Dor. lost and the adjective suffix -en, but if so it is unclear where the medial g came from (AL-Ilkorin/Mablosgen). Alternately, perhaps losgen is the general Ilkorin adjective for “empty” and lost is a variant used only in the Doriathrin dialect.
* losgenadjective. empty
* lostadjective. empty