From Longman Dictionary of Contemporary Englishdrop back (also drop behind) phrasal verbto move more slowly than other people so that they get ahead of you He started out with the leaders but at the first fence he dropped back. Ellen dropped behind to tie her shoelace. → drop→ See Verb table
Examples from the Corpus
drop back• Speed had dropped back and Wallace moved upwards in the second half.• She half-ran, half-walked, taking a wide curve around the villa and dropping back down towards it on the western side.• Then they dropped back out of sight.• I drop back soundlessly, my lips slackened. 