A word for “blossom, inflorescence” in notes on flowers from the same bundle containing Definitive Linguistic Notes (DLN) written in 1959, cognate to Q. lós of similar meaning and serving as the basis for the name S. Lúthien “Daughter of Flowers” (PE17/161). Another word of similar meaning is S. goloth; I think lûth may specifically refer to blooms on a single plant, whereas goloth refers to any collection of flowers.
Sindarin
lúth
noun. blossom
lûth
noun. blossom, inflorescence, blossom, inflorescence [on a single plant]
_ n. Bot. _blossom, inflorescence. >> Lúthien