Sir

Sir is an English honorific derived through Old French from the Latin senior meaning "elder" or "lord." As a pet name, Sir is used with obvious affectionate irony — bestowing the formal title of respect on a companion who has done nothing to earn it except exist and be beloved. There is something delightful about a companion who demands to be addressed with the full dignity of a medieval knight simply by the force of their personality. Sir suggests a companion who takes himself very seriously and expects everyone else to do the same.

Sir holds #276 on the pet name charts and is one of the most effortlessly comic pet names in common use. The formality of the title — typically reserved for knights and men of distinction — applied to a beloved companion creates a delicious tension between dignity and absurdity. Sir works best for companions who have a certain imperious bearing: who expect their food on time, their preferred sleeping spot to remain unoccupied, and general deference from all household members. The joke is that your companion actually lives up to the title.