You may hear よっぽどas よほど(which sounds more formal). This handy word just means that something is to a very great extent, or a greater extent than usual, so. So, perhaps your father's cooking is terrible, but on one occasion its even worse than usual, you might say it is よっぽどまずい.
You can use this word like you would use とても, placing it in front of whatever you want to modify with "really" or "great". I think you can also use it to say something like, "It looks like you've been eating a great deal" or "It looks like you've had a really big appetite lately", although you aren't modifying an adjective there (最近よっぽど食欲があるようだね).
よっぽどis often used with words that show conjecture or observation, such as みたい、らしい、よう、でしょう、etc.