Luxury definition in taxation determines whether items are taxable; interpretive focus must follow constitutional tax scheme. The term luxury covers senses ranging from sumptuous enjoyment and habitual indulgence to items providing comfort beyond necessities; dictionaries and judicial glosses offer varied definitions, and specific statutes have historically taxed non-necessaries. The ambiguity in taxation entries means the word must be construed by reference to the entry's language and the constitutional scheme for taxation and revenue collection, so that what counts as a taxable luxury is determined by contextual statutory interpretation rather than by isolated dictionary or foreign judicial meanings.