ward > guard ("watch and ward" was formerly a common compound sb.)
3 Nor wight nor word might pass out of the gate,
Nor > Neither wight > person, creature
4 But in good order, and with due regard; 5 Utterers of secrets he from thence debarred,
debarred > kept out
6 Babblers of folly, and blazers of crime.
blazers > proclaimers
7 His larumbell might loud and wide be heard,
larumbell > alarm-bell
8 When cause required, but never out of time; 9 Early and late it rang, at evening and at prime.