also myx·a·me·ba(mĭk'sə-mē'bə) n., pl., -bas, also -bas, also -bae, or -bae (-bē). A slime mold at a stage when it is an amoebalike free-swimming cell and before it fuses to form a plasmodium.
a free-living haploid amoeboid cell occurring in the life cycles of the cellular slime moulds and the myxomycetes. In the former they aggregate to form a slug and in the latter a plasmodium.