Well I just looked it up and apparently it isn't true:

Did the word "golf" originate as an acronym for "gentlemen only, ladies forbidden"? That's a common old wives' tale. Or, in this case, more likely an old husband's tale.

No, "golf" is not an acronym for "gentlemen only, ladies forbidden." If you've ever heard that, forget it immediately. Better yet, find the person who told you and let them know it's not true.

Like most modern words, the word "golf" derives from older languages and dialects. In this case, the languages in question are medieval Dutch and old Scots.

The medieval Dutch word "kolf" or "kolve" meant "club." It is believed that word passed to the Scots, whose old Scots dialect transformed the word into "golve," "gowl" or "gouf."

By the 16th Century, the word "golf" had emerged.