Definition of "deceitful"

All theſe are ſeruants to deceitfull men.

c. 1590–1591 (date written), William Shakespeare, “The Two Gentlemen of Verona”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene vii]

Faithfull are the woundes of a friend : but the kiſſes of an enemy are deceitfull.

1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], Proverbs 27:6

This world is all a fleeting show, / For man’s illusion given ; / The smiles of Joy, the tears of Woe, / Deceitful shine, deceitful flow — / There’s nothing true but Heaven !

a. 1826, Thomas Moore, “This World Is All a Fleeting Show”, in The Works of Thomas Moore, stanza 1, page 471, lines 1–5