Strong's Concordance G2435

Original Word: ἱλαστήριον
Transliteration: hilastḗrion
Phonetic Spelling: hil-as-tay'-ree-on
[ἱλαστήριον] neuter of a derivative of G2433; an expiatory (place or thing), i.e. (concretely) an atoning victim, or (specially) the lid of the Ark (in the Temple)

Usages throughout the bible

Romans 3:25 - Whom God hath set forth to be a propitiation G2435 through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;

Hebrews 9:5 - And over it the cherubims of glory shadowing the mercyseat; G2435 of which we cannot now speak particularly.