Here are some possibilities:
* "Flug" could be a misspelling of "flung," which is the past participle of the verb "to fling," meaning to throw something with force.
* "Flug" could be a misspelling of "flu," which is short for influenza, a viral infection.
* "Flug" could be a word from another language. For example, in German, "Flug" means "flight."
If you can provide more context or the full sentence where you saw this word, I can help you understand its meaning.