vain > empty, futile; foolish allurements > charms, baits

5 When them the wary boatman thus bespoke:

bespoke > addressed

6 "Here now behoves us well to advise,

behoves > [it behoves] advise > take stock, consider

7 And of our safety good heed to take; 8 For here before a perilous passage lies,

before > ahead

9 Where many mermaids haunt, making false melodies.

haunt > resort, frequent

212.18