This is the 18482nd most frequent Russian word.
явное
Clear, obvious, evident.
The word 'явное' here means 'clear' or 'obvious', describing the proof as unmistakably indicating his guilt.
Это было явное доказательство его вины.
This was clear evidence of his guilt.
In this sentence, 'явное' describes the effort as noticeable and evident to others.
Он сделал явное усилие объяснить ситуацию.
He made an obvious effort to explain the situation.
The word 'явной' denotes the joy as apparent and perceptible, emphasizing its visibility.