Lexical Definition

‎τεταρταῖος‎ tetartaîos (tet-ar-tah'-yos) fourth ^G:A
from ‎τέσσαρες‎

four days.

• pertaining to the fourth day

Abbott-Smith

τεταρταῖος, -α, -ον (< τέταρτος), [in LXX: II Ki 3:4 A (רְבִיעִי) * ;]
of or on the fourth day: τ. εἶναι (Hdt., τ. γενέσθαι), to be four days dead, Jo 11:39.†

Abbott-Smith References

Liddell-Scott-Jones

τεταρταῖος-αῖος,

Aeolic dialect τετόρταιος [Refs 3rd c.BC+], α, ον, on the fourth day, τ. γενέσθαι to be four days dead, [τεταρταῖοςαίους 5th-6th c.BC: Plato Philosophus “Respublica” 616b. ">Refs 5th c.BC+]

__2 τ. πυρετός quartan fever, [Refs 5th c.AD+]; so without πυρετός, [Refs 5th c.BC+]; πυρετῷ καὶ τεταρταῖοςαίῳ [Refs]; τ. πονεῖσθαι to have fits every four days, [τεταρταῖοςαίῳ μῆνας ἔκαμνε πυρί 3rd c.BC: Callimachus Epicus “Aetia” 3.1.17; λύτρα τεταρταῖοςαίοιο δυσαλγέος οὕνεκα παῦσαν “Rev.Bibl.” 14.295 (from Lycia). ">Refs 5th c.BC+]
__II τεταρταῖοςαίη, ={ἡ τετάρτη}, the fourth day, [Refs 4th c.BC+]
__II.2 quartan fever, [Refs 5th c.AD+]