"Blend of John and William"
The name Johnwilliam is commonly a male name from the "English" origin.
Johnwilliam joins two established English given names, John and William, in a single written form. John goes back to the Hebrew Yohanan by way of Greek Ioannes and Latin Iohannes, and William to the Germanic Willahelm, from wil, will or desire, and helm, protection. The combined one-word spelling first appears in United States birth records in 1979.
The pronunciation of Johnwilliam is JAHN-wil-yum.