The most common meaning of ‘veg out’ is: ‘to relax and do nothing’. It’s like an English way to say ゴロゴロする. The word ‘veg’ is a nickname for ‘vegetable’, so to ‘veg out’ means ‘be still like a vegetable’. However, if you google ‘veg out’ images, you will see pictures of vegetarian restaurants, sandwiches, salad dressings etc. That’s because ‘veg out’ *sounds* like it can also mean ‘Eat a really, really large amount of vegetables!’
A: What are you doing for New Year’s?
B: Nothing much. I’m just going to veg out at home. You?
A: Well, I just bought the ingredients for vegetarian lasagna, so I guess I’m going to ‘veg out’ too.
B: Haha. Very funny.
Are you planning to veg out this New Year’s?
大人からの英会話 getgo 西船橋・荻窪・津田沼・本八幡