Quick Definition
unsettled, unstable
Strong's Definition
inconstant
Derivation: from G1 (Α) (as a negative particle) and a derivative of G2525 (καθίστημι);
KJV Usage: unstable
Thayer's Greek Lexicon
ἀκατάστατος, (καθίστημι), unstable, inconstant, restless: Jas_1:8, and L T Tr WH in also, but less fitly; (cf. Hermae Past. l. ii. mand. 2, 3 πονηρόν πνεῦμα ἐστιν ἡ καταλαλιά, καί ἀκατάστατον δαιμόνιον, μηδέποτε ἐιρηνεῦον, ἀλλά etc.). ((Hippocrates and others) Polybius 7, 4, 6, others (the Sept. Isa_54:11).) #REM: LEFT OFF HERE
Mounce Concise Greek Dictionary
ἀκατάστατος akatastatos 2x
unstable, inconstant; unquiet, turbulent, Jas_1:8 ; Jas_3:8
Abbott-Smith Greek Lexicon
ἀι -κατά -στατος , -ον
( < καθίστημι ),
[in LXX : Isa_54:11 ( H5590 );]
unsettled, unstable: Jas_1:8 ; Jas_3:8 .†
Moulton & Milligan — Vocabulary of the Greek NT
ἀκατάστατος [page 17]
Audollent no. 4 ( b ) 12 (a curse on a leaden tablet from Cnidus) ἀνατίθημι Δάματρι καὶ Κόραι τὸν τὴν οἰκία (ν ) μου ἀκατά [σ ]τατον ποιοῦ (ν )τα . The date ( op. cit. p. 5) is given as B.C. 300 100, though the series may be later (Newton).
Liddell-Scott — Intermediate Greek Lexicon
ἀκατάστατος [Etym: καθίστημι] "unstable, unsettled", Dem.
STEPBible — Tyndale Abridged Greek Lexicon
ἀ-κατά-στατος, -ον (καθίστημι),
[in LXX: Isa.54:11 (סֹעֲרָה) ;]
unsettled, unstable: Jas.1:8, 3:8.†
(AS)