Deduced from Arassuil, conceivably aran+suil. For the meaning, see suilad
Sindarin
suilad
noun. greeting
suilad
gerund noun. greeting
suila-
verb. to greet
suil
noun. greeting
suilannad
gerund noun. greeting, giving of greetings
a pherhael ar am meril suilad uin aran o minas tirith nelchaenen ned echuir
to Samwise and Rose the King’s greeting from Minas Tirith, the thirty-first day of Stirring
suilad
greeting
suilad (i huilad, o suilad), pl. suilaid (i suilaid)
suilad
greeting
(i huilad, o suilad), pl. suilaid (i suilaid)
@@@ Ellanto and Luinyelle suggested this might be an ordinary noun rather than a gerund in a 2023 Discord conversation: discord.com