The dictionary definition of a word is always straight to the point; verbs, names, adjectives are clearly defined and their meaning universal. Spoken language is more fleeting however, and a word definition more than once depends on culture, education or origin. The definition of marriage is a fair example, that varies entirely according to countries and customs. The science definition of Heavens will be world apart from the esoteric definition of the same word, as for the definition of life, it changes with our moods... sometimes glorious... sometimes rotten.
Even dictionaries don't always agree, mostly when History is concerned; the French definition of a name will differ from the English definition, turning a hero into a villain or vice-versa. It's all a matter of perspective. At work, the job definition our boss has in mind seldom agrees with our own; and the art definition of a well known painting don't always reflect our private opinion of it.
Reality changes, and the definition of any given word changes with it, to better reflect our current concerns and our vision of the world surrounding us.
