Flab rat?

Rats are commonly used in laboratory experiments. They have come to be known in English as lab rats, and the term is used figuratively as well as literally. The author was playing on the term in the title by referring to overweight lab rats as flab rats--i.e., flabby rats, fat rats.

Did you look up flab before you asked the question?

What does flab mean?

I understand that you are likely not familiar with the idiom that the play on words is based on, but it seems that you need to do more work taking phrases apart if you are going to be able to use English well.

Asking questions of and engaging native speakers is much more beneficial than looking something up in a dictionary, ehBeth.

Yes! JTT you are always sharp-eyed.

Of course I checked some dics before asking.
Thank you.

Thanks.