Wilho is of Finnish origin and means "willow". It is often considered a diminutive of Wilhelm, which means "resolute protection" or "strong-willed warrior". The name Wilho was particularly popular in Finland during the late 19th to mid-20th centuries, but it has since become less common.
"Wilho experienced a peak in popularity during World War I, with the highest number of births recorded in 1916. However, its usage steadily declined afterwards, falling below double digits by 1924."