"Blend of Willa and Mae"
The name Willamae is commonly a female name from the "American" origin.
Willamae is a compound given name formed by joining Willa and Mae and writing them as a single word. Both elements were established given names in the United States by the early 20th century, and the joined form follows a wider American pattern of attaching a short second name such as Mae directly to a first name. The name first appears in United States birth records in 1912, which fits that pattern rather than an older single-root origin.
The pronunciation of Willamae is WIL-uh-may.