Sentence:  "One kiss, my bonny sweetheart, I'm after a prize to-night,/  But I shall be back with the yellow gold before the morning light;/  Yet, if they press me sharply, and harry me through the day,/  Then look for me by moonlight,/  Watch for me by moonlight,/  I'll come to thee by moonlight, though Hell should <WSD>bar</WSD> the way." 
Meaning of the word marked with <WSD> tags:  To obstruct the passage of (someone or something).