Everyone at the party was in a jocund mood, especially after Dorian and Tabitha made the surprise announcement that they were engaged to be married. —— Merriam-Webster

Though it now sounds indispensable, Mona Lisa was not used as a title for the painting until the 19th century. The source for the name is once again Vasari, who stated confidently that the woman in the picture was a certain Monna Lisa del Giocondo. ('Mona' or 'monna' is a form of address rather than a name: an abbreviation of madonna, literally translated as 'my lady' but as used in 16th-century Italy something more like 'Mistress' or 'Mrs'.) To Italians the painting is and always has been La Gioconda (and to the French, La Joconde or Gioconde). This may be a reference to the same Lisa del Giocondo, but the title has a perfectly plausible existence without her. Giocondo is an adjective, meaning 'jocund', so this traditional name for the painting could have originated as a purely descriptive title - the witty or playful one, the joker-lady, perhaps even the tease. —— Donald Sassoon; The Myth of the Mona Lisa; She's a global icon, celebrated in songs, poetry and Pop Art. Yet, 500 years after Leonardo da Vinci painted the Mona Lisa, we are no closer to unravelling the mystery surrounding the phenomenon. In the latest exclusive online essay from the London Review of Books, Charles Nicholl considers the enduring appeal of the world's most famous portrait; Guardian; March 28, 2002

"I think of her as of a beautiful part of my own youth, and the dream that we are all dreaming seems to darken." That is a natural thought for a letter of condolence, but "Life is a dream" is commonplace by the side of "A dream of a shadow is man." A strange reflection to come after the jubilant outburst with which the poet celebrates the victory of Aristomenes. But the Greeks were not the jocund race they are supposed by many to have been. The shadows are as black as the light is bright, and in this poem a broad belt of darkness comes between two illuminations. —— Bazil Gildersleeve; My Sixty Days in Greece; The Atlantic; Feb 1897

Did you know? (Merriam-Webster)
Don't let the etymology of "jocund" play tricks on you. The word ultimately comes from "jucundus," a Latin word meaning "agreeable" or "delightful." But "jucundus" looks and sounds a bit like "jocus," the Latin word for "joke." The two roots took a lively romp through many centuries together and along the way the lighthearted "jocus" influenced the spelling and meaning of "jucundus," an interaction that eventually produced our modern English "jocund" in the 14th century.