"Stringy flesh" refers to meat or any type of food that has long, thin fibers running through it. It often describes tough or chewy meat that is difficult to cut or tear apart. Full definition
Halve all of the acorn squash and scrape out the seeds and stringy flesh with a spoon. (purplecarrot.com)
One at a time, take each cooled squash half and scrape out stringy flesh into a medium bowl, tossing with 5 - 6 meatballs and 1/2 cup of pasta sauce. (noexcusesnutrition.com)
Scoop out all of the pumpkin seeds and the stringy flesh so that only the meat of the pumpkin is left intact. (jerryjamesstone.com)