What English still means by it
Call someone a crispin in older English and you are naming a shoemaker, usually with a smile. The word turns up in slang lists, comic essays, and dictionaries of familiar speech more often than on a workshop sign. Desk dictionaries still keep a lowercase common noun beside the saint and the given name. The cobbler sense is dated, but it is the sense that makes this a vocabulary item rather than only a baptismal name.
A later market label uses the same spelling for the Mutsu apple, a large green-gold fruit bred in Japan and sold in Britain as Crispin from 1968 because the flesh snaps when bitten. That label rides on the ordinary adjective crisp. It does not continue the cobbler word, even though both ultimately look back to a Latin root for something curled or crimped.
The origin of the word crispin, in the personal-name and cobbler senses, is a Latin hair nickname that the church attached to leather-trade saints, and that English then used as a jocular job title.
A cognomen built on curly hair
Romans used Crispinus as a cognomen, an extra hereditary name. It is a derivative of Crispus, an adjective meaning curly, crimped, or having curled hair, plus the suffix -inus, which formed words of belonging or descent. A Crispus was marked by curls; a Crispinus belonged to that description or that family.
Latin crispus could describe wrinkled cloth as well as hair. English took the adjective separately as crisp, first of wavy hair and wool in Old English, then, much later, of brittle food and bracing air. Sharing a root is not the same as sharing a history: the name did not grow out of the English adjective.
Historical linguists connect Latin crispus to a reconstructed Proto-Indo-European root meaning to turn or bend. That reconstruction is useful and uncertain in equal measure, and it should not be treated as a form anyone in Rome or medieval England would have spoken.
Related given names in other languages keep the Latin shape: French Crépin, Italian Crispino, Spanish Crispín, Portuguese Crispim, Polish Kryspin. They are not English borrowings of one another so much as parallel inheritances of the same cognomen through Christian naming.
English did not inherit the name from Old English. It arrived with Latin hagiography and with Norman French. Medieval documents show Latin Crispinus and Old French Crespin in France from the thirteenth century, and English surname and byname records from the Norman period onward, including the Domesday-era Milo Crispinus. Some of those surnames come from the personal name; some come from an Old French nickname crespin, curly-haired. The two streams are hard to tell apart in a single parish roll.
Saints, a feast, and a false pine
The name stayed current because of Crispin and Crispinian, brothers honoured as third-century martyrs. Legend sends them from Rome to Soissons in Gaul, where they preached and made shoes so they would not live on charity. Their feast is 25 October. Dates for the execution wander: about 285, 286, or, in some older retellings, around 303. The persecuting governor named in the legend is likely fictitious. Historians treat the pair as cult figures whose workshop story mattered more than a recoverable biography.
Shoemakers, cobblers, tanners, and other leather trades claimed them as patrons. Guild processions on the feast day, especially in France and England, kept the names in public hearing. Shakespeare later tied 25 October to the battle of Agincourt in Henry V, which preserved the saints in literary English without inventing the cobbler noun.
A separate medieval tale attached to the Norman family of Gilbert Crispin. Lanfranc, archbishop of Canterbury in the late eleventh century, is reported as saying Gilbert was the first man so nicknamed, and that two of his sons took Crispin as a surname. Family lore then derived the name from curly hair plus a pine, as if the hair stood up like needles. That pine analysis is a learned joke, not the Latin morphology. The real pieces are Crispus and -inus.
When the saint became the craftsman
English could already name a shoemaker's awl as St. Crispin's lance in the early seventeenth century; a 1611 French-English dictionary records the matching French phrase. By the 1640s, writers were using crispin itself for the man who held the awl. Early examples sit in letters and essays rather than in trade ordinances, which is why historical notes flag the common noun as literary at first.
An early-nineteenth-century slang dictionary offered a rival story: a romance in which a prince named Crispin practised shoemaking, the so-called gentle craft. The compiler himself preferred the Soissons martyrs. The prince plot looks like folk explanation after the fact. The mechanism that actually produces the noun is ordinary metonymy: the patron stands for the trade.
In 1867 shoe workers in Milwaukee founded the Order of the Knights of St. Crispin, which for a few years was among the largest labour organisations in the United States before fading in the 1870s. Members were Crispins in the union sense, a last public flowering of the same transferred name.
The meaning therefore moved in clear stages: a Roman description of hair, a family name, a saint, a humorous English word for cobbler, and briefly a union identity. The pronunciation did not have to change for any of those steps.
The apple on the greengrocer's shelf is a coincidence of spelling. The fact worth keeping is smaller: English borrowed a Latin formation from curly, let the church attach it to leatherworkers, and then, in the seventeenth century, used the saint as a wry name for the man at the last.