2 And the other brother gan his helm unlace,
gan > did; began to helm > helmet
3 Both fiercely bent to have him disarrayed;
bent > (Lit. and fig.)
4 Till they spied where towards them did pace 5 An armed knight, of bold and bounteous grace, 6 Whose squire bore after him an ebon lance
squire > attendant (esp. waiting on a knight) ebon > {Ebony, made of ebony, a tree of the family Ebenaceae, esp. Diospyros ebenus, producing hard black wood}
7 And covered shield. Well kenned him so far space
covered > (See 107.33) kenned > recognized so far space > at such a distance
8 The enchanter by his arms and amenance,
The enchanter > [Archimago] arms > {Arms and armour} amenance > bearing