根据题主的REITs提示，Anchor Tenant是指固定租户，也称为“锚定租户”。

锚定租户是指作为购物中心、办公楼或商业区主要租户的企业。

英文释义供参考：In retail, an "anchor tenant", sometimes called an "anchor store", "draw tenant", or "key tenant", is a considerably larger tenant in a shopping mall, often a department store or retail chain. They are typically located at the ends of malls. With their broad appeal, they are intended to attract a significant cross-section of the shopping public to the center. They are often offered steep discounts on rent in exchange for signing long-term leases in order to provide steady cash flows for the mall owners.