Feminine of Clement, from Latin 'clemens' meaning merciful and gentle.
Clementina is the full, stately Latinate feminine form of Clement, derived from the Latin *clemens*, meaning gentle, mild, or merciful — virtues prized so highly by the early Christian church that they were woven directly into the papal name tradition. Pope Clement I, venerated as a saint and considered by some traditions to be the third successor of Peter, established the name's ecclesiastical prestige in the first century AD. From Rome, the name spread across Catholic Europe in its various forms: Clément in France, Clemente in Italy and Spain, Clementine in France and Germany, and Clementina in the Iberian Peninsula and Italian states.
The name carried genuine aristocratic weight in early modern Europe. Maria Clementina Sobieska, the Polish princess who married the exiled Jacobite claimant James Francis Edward Stuart in 1719, became one of its most romantic bearers — her clandestine flight from imprisonment in Innsbruck to reach her husband captivated all of Europe and earned her enormous public sympathy. In Britain, Clementine (the more commonly used anglicized form) is forever associated with Clementine Churchill, née Hozier, the formidable wife of Winston Churchill, whose intellect and political acumen were acknowledged even by those who downplayed her role publicly.
Clementina, as the longer and more ornate variant, was favored in 18th and 19th-century naming practice when elaborate feminine names were fashionable. Today it reads as grandly vintage, a name poised between the antique and the newly rediscovered, inviting the casual nickname Clemmie while losing none of its underlying gravitas.