purveyor

n. officer who goes ahead to secure foodand lodging for the king and his retinue,harbinger （为王室出行而筹办食宿）打前站的人，先行官。
△Mac.1.6.21:“We coursed him at the heels,and had a purpose / Tobe his purveyor；”i. e. We followed closely at his heelswith the hope of outstripping him. 我们紧紧地追赶他，存心想做他的先遣使。