1) At a previous time 2) At one time 3) Erst 4) Erstwhile 5) In an earlier period or age 6) In time just past 7) In time past 8) Insect eating mollusc once 9) Just now 10) Née 11) Once Found on https://www.crosswordclues.com/clue/formerly
For'mer·ly adverb In time past, either in time immediately preceding or at any indefinite distance; of old; heretofore. Found on http://www.encyclo.co.uk/webster/F/64