weened > imagined, supposed
2 Was to them done, their entrance to forestall, 3 Till the squire began nigher to approach; 4 And wind his horn under the castle wall,
wind > blow (cf. 108.3-5)
5 That with the noise it shook, as it would fall:
That > [So that] as > [as if]
6 Eftsoons forth looked from the highest spire
Eftsoons > Thereupon; before long
7 The watch, and loud to the knights did call,
watch > sentinel
8 To weet what they so rudely did require.