Vert, a stag's head caboshed, between the attires a cross floretty Or, a chief dancetty of the last, impaling per fess wavy argent and azure, a scallop shell between two estoiles in pale, all counterchanged.
In designing the shield — the central element in what is formally called the heraldic achievement
— a bishop has an opportunity to depict symbolically various aspects of his own life and heritage, and to highlight aspects of Catholic faith and devotion that are important to him. The formal description of a coat of arms, known as the blazon, uses a technical language, derived from medieval French and English terms, which allows the appearance and position of each element to be recorded precisely.
A diocesan bishop shows his commitment to the flock he shepherds by combining his personal coat of arms with that of the diocese, in a technique known as impaling. The shield is divided in half along the pale or central vertical line. The arms of the diocese appear on the dexter side — that is, on the side of the shield to the viewer's left, which would cover the right side (in Latin, dextera) of the person carrying the shield. The arms of the bishop are on the sinister side— the bearer's left, the viewer's right.
The field of the diocesan arms is divided gold (Or) and green (vert) by a jagged line that creates the impression of mountain peaks. The diocese comprises the entire State of Vermont, named by the French Catholic explorer Samuel de Champlain. On his arrival in the area in July 1609, he is reported to have said, " Voila, les monts verts!"—"Behold, the green mountains!" The first priests in what is now Vermont were French Jesuit missionaries, including Saint Isaac Jogues, who visited the area at least four times.
When the Diocese of Boston was established in 1808, it included all of New England, and the arms of both the now-Archdiocese of Boston and the Diocese of Burlington include a Cross floretty, that is, with a fleur-de-lis appended to the ends of each arm. This flower was a symbol of France beginning in the Middle Ages. The City of Burlington was probably named after Richard Boyle, third Earl of Burlington (1694-1753), when it was organized in 1785. By the time the Diocese was established in 1853, the title of Earl of Burlington was held by William Cavendish (1808-1891), whose coat of arms depicted three stags' heads painted silver on a black field (Sable, three stags' heads caboshed argent). The arms of the Diocese of Burlington include a stag's head in gold to make this connection. The Bishop's personal coat of arms is divided horizontally by a wavy line (perfess wavy) into two sections painted respectively white and blue (argent and azure). Following high school, Bishop McDermott attended the United States Coast Guard Academy in New London, Connecticut, and this allusion to the sea refers to those days as they were important to his discernment to become a priest, as well as to the waters of Lake Champlain. Two six-pointed wavy stars (estoilles) appear, one in the "sky" to refer to Our Lady, the Star of the Sea, and the other in the "sea" itself. A six-pointed star is a traditional symbol not only of Our Lady but also of Saint Joseph, as a descendant of the royal house of King David. Its position here depicts the holiness of Saint Joseph as a reflection of that of his Immaculate spouse. Between the stars is a scallop shell, a traditional attribute of Saint John the Baptist, the Bishop's baptismal patron saint. The shell is divided along the same wavy line as the shield, as if it were being dipped into the water at the moment of conferring Baptism. The shell and the stars are all painted counterchanged, that is, blue where the field is white, and white where the field is blue. On the scroll below the shield is inscribed the Bishop's motto. It is a phrase perhaps most familiar from a prayer written by Saint Theresa of Avila on a scrap of paper she used for a bookmark. "Nada te turbe, "it begins — that is, "Let nothing disturb you." — and it concludes with the line, "Solo Dios basta," which means, "God alone suffices." "The shield is ensigned with external elements that identify the bearer as a Bishop. A gold processional cross appears behind the shield. The galero or 'pilgrim's hat" is used heraldically in various colors and with specific numbers of tassels to indicate the rank of a bearer of a coat of arms. A bishop uses a green galero with three rows of green tassels.