Lactobacillaceae lac·to·ba·cillaceae uncommon noun 1. lactic acid bacteria and important pathogens; bacteria that ferment carbohydrates chiefly into lactic acid Synonymsfamily LactobacillaceaeLactobacteriaceaefamily Lactobacteriaceae Related words Broader terms bacteria family Parts Monera Part of genus Lactobacillusgenus Diplococcusgenus Streptococcus WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.