The Vocalibrate dictionary

parsimony

US/ˈpɑːrsəˌmoʊni/GB/ˈpɑːsɪməni/noun

the principle of choosing the simplest explanation that fits the facts

By the rule of parsimony, the doctor looked for one illness that explained every symptom, not three separate ones.

Near in meaning
simplicityeconomy
In the family
parsimonious

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