The phrase "lived by" is a common expression that refers to a person's guiding principles or values. Some synonyms for "lived by" include "abided by," "followed," "adhered to," "observed," and "upheld." These words indicate a commitment to a particular set of beliefs or standards. Additionally, other phrases that have a similar meaning to "lived by" include "sworn by," "stood behind," and "vowed to." Using these synonyms and related phrases can provide more nuance and depth to a communication when describing a person's beliefs or values.