Lexical Definition

‎ἱλάσκομαι‎ hiláskomai (hil-as'-kom-ahee) to propitiate G:V
middle voice from the same as ‎ἵλεως‎

be merciful, make reconciliation for.

Usage: 10 forms in 13 verses
Form Translated As     In Verse(s)
ἱλάσκεσθαι to make propitiation for Heb.2.17
ἱλάσθητί do be merciful Luke.18.13
ιλασθήναι to atone LXX.2Kgs.24.4
ιλάσθητι atone LXX.Ps.25.11LXX.Ps.79.9LXX.Dan.9.19
ιλάσθησ you atoned not LXX.Lam.3.42
ιλάσθη lord dealt kindly LXX.Exod.32.14
ιλάση shall atone LXX.Ps.65.3
you shall atone LXX.2Chr.6.30
ιλάσεται he shall atone LXX.Ps.78.38
ιλάσεταί shall deal kindly LXX.2Kgs.5.18
ίλασεταί shall deal kindly LXX.2Kgs.5.18

Abbott-Smith

ἱλάσκομαι (< ἵλαος = ἵλεως), [in LXX (cf. Westc., Epp. Jo., 85 f.) for סלח, IV Ki 5:18 24:4, Ps 24(25):11*, La 3:42, Da TH 9:19; כּפר pi., Ps 64(65):3* 77(78):38 78(79):9*; נחם ni., Ex 32:14, Es 4:17*;]
1. in cl., c. acc. pers., to conciliate, appease, propitiate (= ἐξιλάσκομαι, Ge 32:20, Pr 16:14, Ma 1:9, al.).
2. In LXX (Thackeray, Gr., 270, f.), Inscr. (Deiss., BS, 224 f.), and NT, to be propitious, merciful (c. dat. rei, Ps 78(79):9*, al.): c. dat. pers. (IV Ki 5:18), Lk 18:13.
3. As in Philo (= ἐξιλάσκ-, in LXX: Ez 43:22, al.), to expiate, make propitiation for: τ. ἁμαρτίας, He 2:17 (Cremer, 301 ff., 735).†

Abbott-Smith References

Book Refs
Genesis 32:20
Exodus 32:14
2 Kings 5:18 · 24:4
Ezra 4:17
Psalms 25:11* · 65:3* · 78:38 · 79:9*
Proverbs 16:14
Lamentations 3:42
Ezekiel 43:22
Daniel 9:19
Malachi 1:9
Luke 18:13
Hebrews 2:17

Liddell-Scott-Jones

ἱλάσκομαι-κομαι,

future ἱλάσομαι [] [Refs 5th c.BC+] Oracle texts cited in [Refs 2nd c.AD+] also ἱλάξομαι [Refs 3rd c.BC+]aorist 1 ἱλάσκομαιάμην, Epic dialect participle ἱλασσάμενοι [Refs 8th c.BC+], Epic dialect subjunctive 2nd pers. singular ἱλάσσεαι [Refs], -ηαι [Refs 3rd c.BC+]; infinitive ἱλάσσασθαι [Refs 3rd c.BC+] —passive (see. below [Refs]. [ regularly (written ι, not ει, [Refs 4th c.BC+]; [Refs 8th c.BC+]: (ἵλαος):—appease, in [Refs 8th c.BC+]; σπονδῇσι θύεσσί τε ἱλάσκεσθαι (i.e. θεούς) [Refs 8th c.BC+]; with participle, ἱλάσκομαι πέμπων by presenting, [Refs 5th c.BC+]; τοῦτον (i.e. θεὸν) ἱλάσκου ποῶν μηδὲν ἄτοπον [Refs 4th c.BC+]; of the dead as heroized, θυσίῃσί τινα . [Refs 5th c.BC+]

__2 of men, conciliate, . τινὰ χρήμασι [Refs]; πῶς ἱλασόμεθα καὶ τίνι λόγ; [Refs 5th c.BC+]
__3 expiate, τὰς ἁμαρτίας [NT]
__II passive with future ἱλάσομαι, also ἱλασθής ομαι variant in [LXX]aorist 1 ἱλάσθην[LXX]:—to be merciful, gracious, τινι [same places]; ἱλάσθητί μοι τῷ ἁμαρτωλῷ [LXX+NT]infinitive, ἱλάσθη κύριος περιποιῆσαι τὸν λαόν[LXX]

LSJ Scripture Refs: Heb.2.17LXX.Exod.32.14Luke.18.13LXX.Ps.77.38*LXX.Exod.32.14