from konia (dust, by analogy, lime); TDNT - 3:827,453
AV - whited 2; 2
1) to cover with lime, plaster over, whitewash
1a) the Jews were accustomed to whitewash the entrances to their sepulchres, as a warning against defilement by touching them
1b) term applied to a hypocrite who conceals his malice under an outward assumption of piety