Sindarin 

-in

suffix. adjective suffix

-ren

suffix. adjective suffix

@@@ perhaps a later, S-only, innovation

ring

adjective. cold

Sindarin [Ety/383, S/436, VT/42:13, X/RH] Group: SINDICT. Published by

ring

cold

(adj.) ring (no distinct pl. form),

ring

cold

(no distinct pl. form)

-eb

suffix. adjective suffix

Sindarin [WJ/337; WJ/412] Group: Eldamo. Published by

-en

suffix. adjective suffix

Sindarin [PE17/098; RGEO/62; SA/lin¹; SD/129] Group: Eldamo. Published by

-iel

suffix. adjective suffix

helch

bitterly cold

(lenited chelch; pl. hilch);

rim

cold pool/lake

; no distinct pl. form except with article (idh rim), coll. pl. rimmath. Note: a homophone means ”crowd, great number, host”.