"Although it was a poor enough meal, they ate every bit of it."
"It was poor enough meal, but they ate every bit of it."
This is an inverted sense of 'enough'. I think in this case it means something like, "Although the meal was poor enough that they normally wouldn't want to eat it, ..."
"Although it was not really good enough to eat, ..."
It seems to mean 1.
Student or Learner