Final answer:
The word that defines 'done out of duty or routine; performed mechanically' among the given options is 'Perfunctory'.
Step-by-step explanation:
The word among the provided options that means 'done out of duty or routine; performed mechanically' is Perfunctory. The term 'Perfunctory' encapsulates the notion of doing something routinely, without much care or attention, often out of a sense of obligation or duty rather than enthusiasm. In contrast, 'Presumptuous' refers to overstepping bounds or taking liberties, 'Paraphernalia' refers to miscellaneous items required for a particular activity, and 'Credulity' refers to the tendency to readily believe that something is real or true.
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