An adjective in the Qenya Lexicon of the 1910s glossed “open” under the early root ᴱ√AFA “open, begin” (QL/29).
Early Quenya
lat
noun. flap, small hinged door, lid
apte
adjective. open
furu
noun. lie
tendl
noun. string
A word appearing in The Qenya Phonology of the 1910s whose plural tendilli was glossed “pieces of string” (PE12/25). Its root was given as ᴱ√TEME, which elsewhere was glossed “tie” (QL/91).
A word appearing as ᴱQ. lat (latt-) “flap, small hinged door, lid” in the Qenya Lexicon of the 1910s, which Tolkien considered deriving from the early root ᴱ√LAPA “enfold” (QL/51).
Neo-Quenya: For purposes of Neo-Quenya, I think this word can be salvaged as ᴺQ. lat (latt-) derived from the later root √LAT “open”, perhaps from primitive lattă with an original sense “opening”.