Keep in mind that urban dictionary is for extremely informal meanings and slang. In a sentence like yours that is much more formal, an urban dictionary definition doesn’t apply. The word ensuing is formal vocabulary so in that case it means literally the year plus another half a year.

Tim's answer is quite correct and his advice is also correct.

I would just add that the phrase "ensuing year and a half" simply means "in the following/in the coming next 18 months..."