This is the 1989th most frequent French word.
visible
Able to be seen.
Here 'visible' is used as an adjective to describe the moon, indicating that it could be clearly seen.
La lune était parfaitement visible cette nuit.
The moon was perfectly visible tonight.
In this sentence, 'visible' indicates the possibility of seeing someone, but only under specific conditions or from a certain distance.
Il n'était visible que de loin à cause de la foule.
He was only visible from afar because of the crowd.
Here, 'visible' is used metaphorically to express how the effects of pollution can be noticeably observed or perceived.