Likely a variant of Gianna or Giovanna, ultimately from Hebrew Yohanan, meaning "God is gracious."
Geonna is a name that lives at the creative edge of feminine naming, a phonetic construction that draws on several familiar traditions while arriving at something distinctly its own. Its sound aligns most closely with Sionna — the Irish name derived from the River Shannon, possibly meaning "possessor of wisdom" — and with Gianna, the Italian feminine form of John (from the Hebrew Yohanan, "God is gracious"). The initial G gives it a harder, more assertive opening than the softer Sionna, while the -onna ending connects it to a family of names (Donna, Fiona, Leona) that have long histories in English use.
It may also be read as a creative respelling of Shawna or Joanna, reflecting the broader twentieth-century American practice of reshaping familiar names with new orthography — a practice that produces names that look invented but sound traditional when spoken aloud. In this sense Geonna participates in a long tradition of phonetic customization: parents hear a sound they love and choose a spelling that makes it visually distinctive, ensuring their child's name stands apart on paper even if it blends in when called across a playground. Geonna is genuinely rare, which means its bearers tend to carry it as a mark of individuality.
It has the visual weight of a two-syllable name (jee-ON-ah or jee-AHN-ah, depending on regional accent) but can expand to three depending on how the speaker lands on it. Like many names at this edge of invention and tradition, it will belong most fully to whatever meaning its bearer gives it — which is, perhaps, the freest kind of name there is.