Lexical Definition

‎αὐστηρός‎ austērós (ow-stay-ros') severe ^G:A
from a (presumed) derivative of the same as ‎ἀήρ‎ (meaning blown)

austere.

• rough (properly as a gale), i.e. (figuratively) severe

Abbott-Smith

** αὐστηρός, -ά, -όν (< αὔω, to dry up), [in LXX: II Mac 14:30*;]
prop., stringent, harsh to the taste. Metaph., in Inscr., of a rough country; of disposition and manners, strict, severe (as in π., of an inspector; MM, s v): Lk 19:21, 22.†
SYN.: σκληρός (Tr., § xiv).

Abbott-Smith References

Liddell-Scott-Jones

αὐστηρός, ά, όν,

(αὕω) harsh, rough, bitter, ὕδωρ[Refs 5th c.BC+]; οἶνος αὐ., opposed to γλυκύς, [Refs 5th c.BC+]; of country, rugged, τόποι[Refs 1st c.BC+]: metaphorically, harsh, crabbed, ποιητής[Refs 5th c.BC+]; severe, unadorned, ἡ πραγματεία ἔχει αὐ. τι[Refs 2nd c.BC+]severe, [Refs]. adverb -ρῶς, κατεσκευάσθαι[Refs 1st c.BC+]

__b in moral sense, rigorous, austere, [Refs 4th c.BC+]; αὐ. καὶ αὐθάδης[Refs 1st c.BC+], Vett. Val.75.11; strict, exacting, [NT+2nd c.AD+]; αὐστηρότερον, τό, excessive rigour, [Refs 2nd c.AD+]. adverb -ρῶς[Refs 1st c.BC+] comparative -ότερον [LXX]

_{LSJ Scripture Refs: Luke.19.21}