2 As to descry the crafty cunning train

train > wile, trick

3 By which Deceit does mask in visor fair,

mask > {Disguise [herself]; take part in a masquerade} visor > outward appearance

4 And cast her colours, died deep in grain,

cast > arrange, dispose (as an artist might when painting)

5 To seem like Truth (whose shape she well can feign), 6 And fitting gestures to her purpose frame, 7 The guiltless man with guile to entertain?

entertain > engage, keep occupied

8 Great mistress of her art was that false dame, 9 The false Duessa, cloaked with Fidessa's name.

107.2