Lost Backlinks tool shows backlinks the researched domain has lost in the past 90 days, along with the date of loss.
Donor URL - the referring page.
Acceptor URL - the page that received the backlink.
Anchor - the visible, clickable text in a hyperlink
Serpstat Page Rank (SPR) - a score on scale from 0 to 100 which measures the page authority. Serpstat Page Rank predicts how influential a URL might be based on the number of pages linking to it. Links are not measured with equal weight, so a strong link will have a relatively stronger influence on URLs.
Serpstat Trust Rank (STR) - a score on scale from 0 to 100 which measures the site authority based on how authoritative and trusted are the sites linking to the site in question. A site closely linked to trusted site can obtain higher trust rank scores, while a site which has some questionable links would get a much lower score.
Link Type - follow or nofollow link, i.e. a link that passes link juice or doesn't.
First Indexed - the first time the crawler detected the backlink
Last Seen - the last time the crawler indexed the backlink
Date Lost - the date of backlink loss.