erst UK /ɜːst/US /ɝst/adverb 3adjective 1 adverb3 •(literary, no longer used) Formerly, once, erstwhile.When lofty trees I see barren of leaves Which erst from heat did canopy the herd — 1609 •(no longer used) First of all, before (some other specified thing).Consider what I erst have been and what thou seest me now: — 1567 •(no longer used) Sooner (than); before. adjective1 •(no longer used) First.
