S: (n) mother (a stringy slimy substance consisting of yeast cells and bacteria; forms during fermentation and is added to cider or wine to produce vinegar)
S: (n) mother (a term of address for an elderly woman)
S: (n) mother (a term of address for a mother superior)
S: (n) mother (a condition that is the inspiration for an activity or situation) "necessity is the mother of invention"