"Blend of Ally and Anna"
The name Allyanna is commonly a female name from the "English" origin.
Allyanna reads as a joining of the short form Ally, familiar in English as a pet form of Alice, Alison or Alexandra, and Anna. It is not attested in the US birth record before 2000, and no meaning is documented for it in a source language, which fits a modern formation built from those two familiar elements rather than an inherited name. Similar spellings such as Alianna and Alyanna appear in the same period, so the exact spelling is likely one of several recent American coinages from the same parts.
The pronunciation of Allyanna is al-ee-AN-uh.