Quenya 

castol

helmet

castol noun "helmet", synonyms tholon (q.v.), sól (q.v), also variant castolo ("k")(PE17:186, 188)

castol(o)

noun. helmet

Quenya [PE17/186; PE17/188] Group: Eldamo. Published by

sól

helmet

sól, also solma or solos, noun variant words apparently for "helmet", cf. castol, q.v. (PE17:188)

tholon

helmet

tholon noun "helmet", variant of castol (q.v.), though Tolkien might have mistakenly marked it as Quenya instead of Sindarin (PE17:186)

cassa

helmet

cassa ("k")noun "helmet" (KAS; though spelt cassa also in the Etymologies as printed in LR, VT45:19 indicates that Tolkien's own spelling was kassa). Cf. carma in a later source.

harna

helmet

harna (3) noun "helmet" (VT45:21)

harpa

helmet

harpa noun "helmet" (VT45:21)

þolon

noun. helmet