
1) Artful 2) Crafty 3) Cunning 4) Dishonest 5) Dodgy 6) Foxy 7) Guileful 8) Like or befitting a knave 9) Marked by skill in deception 10) Mischievous 11) Roguish 12) Slick 13) Tricksy 14) Tricky 15) Untrustworthy 16) Waggish 17) Wily 
Found on 
https://www.crosswordclues.com/clue/knavish

1) Base 2) Crafty 3) Foxy 4) Guileful 5) Sly 6) Tricksy 7) Wily 
Found on 
https://www.crosswordclues.com/clue/knavish

• (a.) Mischievous; roguish; waggish. • (a.) Like or characteristic of a knave; given to knavery; trickish; fraudulent; dishonest; villainous; as, a knavish fellow, or a knavish trick.
Found on 
http://thinkexist.com/dictionary/meaning/knavish/
Knav'ish  adjective   1.  Like or characteristic of a knave; given to knavery; trickish; fraudulent; dishonest; villainous; as, a 
 knavish fellow, or a 
 knavish trick. '
 Knavish politicians.' 
 Macaulay.   2.  Mischievous; roguish; waggish. « Cupid is 
 knavi...Found on 
http://www.encyclo.co.uk/webster/K/14

like or befitting a knave; untrustworthy; dishonest. · waggish; roguish; mischievous.
Found on 
https://www.infoplease.com/dictionary/knavish
  No exact match found.