Lexical Definition

‎ἀναντίῤῥητος‎ anantírrhētos (an-an-tir'-hray-tos) indisputable ^G:A
from ‎Α‎ (as a negative particle) and a presumed derivative of a compound of ‎ἀντί‎ and ‎ῥέω‎

cannot be spoken against.

• indisputable

Abbott-Smith

† ἀν-αντί-ρητος (T, -ρρητος), -ον (< ῥητός, spoken), [in Sm.: Jb 11:2 33:13*;]
not to be contradicted, undeniable: Ac 19:36 (MM, VGT, s.v.).†

Abbott-Smith References

Liddell-Scott-Jones

ἀναντίρρητος-ρρητος, ον,

not to be opposed, [Refs 2nd c.BC+]; undeniable, [NT+2nd c.AD+]. adverb -τως without opposition, by consent, [Refs 2nd c.BC+]; incontrovertibly, [Refs 6th c.AD+]; without gainsaying, [NT]

_{LSJ Scripture Refs: Acts.19.36 ☩ Acts.10.29}