family Lactobacillaceae fa·mi·ly·lactobacillaceae uncommon noun 1. lactic acid bacteria and important pathogens; bacteria that ferment carbohydrates chiefly into lactic acid SynonymsLactobacillaceaefamily 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.