καρδιογνώστηςkardiognṓstēs

Same root

• καρδίαkardía · G2588the heart, i.e. (figuratively) the thoughts or feelings (mind); also (by analogy) the middle
• γινώσκωginṓskō · G1097to "know" (absolutely) in a great variety of applications and with many implications (as follow, with others not thus clearly expressed)

Where it appears

Appears 2 times in the Bible.

• Acts 1:24 Then they all prayed, “O Lord, you know every heart. Show us which of these men you have chosen
• Acts 15:8 God knows people’s hearts, and he confirmed that he accepts Gentiles by giving them the Holy Spirit, just as he did to us.