Sentence:  [T]he ebbed man, ne'er loved till ne'er worth love, / Comes deared by being lacked. This common body, / Like to a vagabond flag upon the stream, / Goes to and back, <WSD>lackeying</WSD> the varying tide, / To rot itself with motion. 
Meaning of the word marked with <WSD> tags:  To attend, wait upon, serve obsequiously.