Simplex rhymes with:
timeplex, adaptaplex, cineplex, duplex, mediplex, metroplex, multiplex, starplex, timeplex, adaptaplex, berlex, cineplex, duplex, mediplex, metroplex, multiplex, oraflex, starplex, stratoflex, teleflex, telex, timeplex
Simplex sounds like:
sample's, samples, shambles, simplesse, snapple's, snapples, sniffles, snowball's, snowballs, snowfalls, snowflake, snowflakes, snowmobiles, snowplows, someplace, sonnenblick, symbol's, symbolic, symbolics, symbolize, symbolizes, symbols