sign(sb)in
—phrasal verbwithsignverbuk/saɪn/us/saɪn/
tosignyournameor thenameof someone who isvisitingyou in abook, inorderto beallowedtoenterabuildingsuch as anofficeorhotel
签到，登记
Newsecuritymeasuresrequireallvisitorstosignin at thereceptiondeskandweara visitor'sbadge.新安全措施要求所有访客都在接待处登记并佩戴访客证。