Usage: 2 forms in 3 verses
Form Translated As     In Verse(s)
πυρίκαυστοσ scorched LXX.Isa.64.11
πυρίκαυστοι scorched LXX.Isa.1.7LXX.Isa.9.5

Liddell-Scott-Jones

πυρίκαυστος (purikaustos) scorched G:N-M

πυρίκαυστος-καυστος, ον,

burnt in fire, [Refs 8th c.BC+]; in late Epic dialect πυρίκαυστος-καυτος, Epic. in [Refs 4th c.AD+]

__2 caused by a burn (or scald,[Refs 5th c.BC+]; π. [ἕλκη] [Refs 5th c.BC+]
__3 πυρίκαυστον, τό, plaster for a burn, [Refs 4th c.BC+]
__II inflammatory, in the form -καυτος, [Refs 5th c.BC+]
__II.2 inflamed, ὑπερῴα πυρίκαυτος [Refs 2nd c.AD+]