gladh-

verb. to laugh, to laugh [at a joke], *guffaw

This word is not compatible with the name Lalaith “Laughter” attested in The Silmarillion. The most likely explanation of this name is that it is the unattested verb ✱lala- “laugh” with the abstract noun suffix -th seen in tirith “watch(ing)” and sirith “flowing”. This indicates a primitive form ✶lala- instead of ✶glada- (both primitives produce Quenya lala-). If you were to accept gladh- as the Sindarin word for “laugh”, then the word for “laughter” would perhaps be the equivalent abstract noun ✱gladhath, and the name Lalaith might be a mix of Quenya and Sindarin. @@@ Neo-Sindarin uses

gladuial

place name. *Twilight Wood

Another name for Nan Elmoth appearing on the Silmarillion map from the 1950s (WJ/183, 188 note #48). Christopher Tolkien stated in his notes that he could not find this name anywhere else in his father’s writings, but Christopher apparently forgot that it had appeared as a rejected name in “The Lay of Leithian Recommenced” from the same period, revised to Gilammoth and finally to Nan Elmoth (LB/349). The name appears to be a combination of glad “wood” and uial “twilight”.

lala-

verb. to laugh