From Latin 'peregrinus' meaning pilgrim or traveler; also the name of a beloved hobbit in Tolkien's works.
Peregrin descends from the Latin peregrinus, meaning traveler, foreigner, or pilgrim — someone who journeys far from home. The word is built from per- (through) and ager (field, land), yielding the image of one who passes through foreign lands. In medieval Christian culture, peregrinus was a title of spiritual honor: the pilgrim who traveled to Jerusalem, Santiago de Compostela, or Rome undertook an outer journey that mirrored an inner one, and the peregrine falcon took its name from this same root because it was typically caught while passing through on migration rather than at its nest.
The name was carried by several early Christian saints, including San Pellegrino (the Italian variant), which is why it appears across European naming traditions in forms from Peregrinus to Pellegrino to Pèlerin. R. Tolkien's The Lord of the Rings.
Tolkien — a medievalist and philologist — chose the name with full awareness of its Latin roots, and Pippin's arc enacts the etymology: he is the wanderer, the one who travels farthest from home, who grows the most, and who ends his journey as Thain of the Shire and a Knight of Gondor. Tolkien's work gave the name a warmth it might not otherwise have had, anchoring it to a character who is simultaneously foolish, courageous, and deeply lovable. As a given name today, Peregrin appeals to parents drawn to the tradition of the literary pilgrim, to the peregrine falcon's wild precision, and to a cadence that is unmistakably classical without being stiff. It is a name that implies a life of movement and discovery, and the ready-made nickname Pip or Perry gives it a gentler, everyday face.