What does "damn" exactly mean in this sentence?

Question

Today I came across sentence which was:

People are no damn good.

It got me into thinking that since the word "damn" has been used before "good", a noun, it should be an adjective and the only meaning of damn as an adjective I could find was - "very, extremely" but then does it imply that people are not extremely good although they are but not so much.

Answer 1

'Damn' works here as an interjection giving an emphasis to the whole expression 'people are no good' (=~ are bad).

Answer 2

From the Urban Dictionary, I select the meanings which fit to your sentence:

1. An expression of dismay.
2. An expression of awe.
3. "Giving a damn", the act of caring about something.
4. The act of condemning someone, most often to hell or an equivalent place.
5. "Damn you", a verbal middle finger equivalent to "go to hell".
6. An expression of surprise.
7. "Damn well", a sort of sentence enhancer, most often used with the word "better".
8. An adjective you can stick before phrases like "near" and "close to" to raise the sentence's severity.
9. An exclamation interchangeable with "Wow".
10. An adjective you can stick in front of absolutely any noun to add a feeling of stigma to your sentence.

(I previously had an improperly documented answer.)