This is the 447th most frequent German word.
trotzdem
"Nevertheless" or "despite that."
In this sentence, 'trotzdem' is used as an adverb to introduce a statement contrary to the prior context, showing contrast.
Es regnete stark, trotzdem gingen wir spazieren.
It was raining heavily, nevertheless, we went for a walk.
In this case, 'trotzdem' introduces a concession clause, linking it to the following explanation.
Trotzdem das Wetter schlecht war, fand das Konzert draußen statt.
Although the weather was bad, the concert took place outdoors.
Here 'trotzdem' serves to emphasize a surprising or unforeseen action despite mentioned circumstances.