* A nickname: It could be a shortened version of a Spanish name like "Miguel" or "Michaela."
* A foreign name: It could be a name from another language, possibly Russian, Slovenian, or Croatian.
* A misspelling: It could be a typo for a similar word, such as "mira" (look) or "mia" (mine).
Without more context, it's impossible to know the exact meaning of "miha" in Spanish.
Please provide more information about where you encountered the word or what it refers to.