Flexer rhymes with:
exar, boxer, daxor, elixir, exar, faxer, fixer, indexer, luxor, mixer, multiplexer, paxar, saxer, sixer, taxer
Flexer sounds like:
felger, felker, filigree, flasher, flashier, flaugher, fleeger, fleischauer, fleischer, fleischhacker, fleisher, flesher, flicker, fluker, folger, folker, fulcher