cold call

n.（名词）
A telephone call or visit made to someone who is not known or not expecting contact, often in order to sell something.
陌生电话，推销电话：打给陌生人或不希望被联络的人的一通电话或是拜访，常常是为了推销东西 (来源：专业英语学习网站 http://www.EnglishCN.com)

e.g.

When 3i, the UK private equity firm, cold-called Little Sheep, it discovered it was not the first potential investor to contact the Chinese restaurant chain.

当英国私人股本公司3i主动联系小肥羊(Little Sheep)时，它发现，自己并不是第一个与这家中国连锁餐厅接洽的潜在投资者。