This is the 1999th most frequent German word.
glücklich
Happy; fortunate.
Here, 'glücklich' expresses the state of happiness of the speaker.
Ich bin glücklich, dass du hier bist.
I am happy that you are here.
'Glücklich' is used here to describe something fortunate or lucky.
Das ist ein glücklicher Zufall.
That is a happy coincidence.
In this sentence, 'glücklich' describes an emotional state or feeling of joy.