Correct spelling, explanation: visibly is an adverb that comes from the words visible and vision. However, the origin of visibly can be tracked in the Latin form videre, which meant to see. Later the word evolved into the form visibilis and was also affected by Old French. When it comes to English, visibly entered it in the times of the Middle Ages. In modern English visibly functions both in a written and spoken language.

Definition of visibly:
1. adverb – in a clear, obvious way,
The woman was visibly scared when the man approached so I called the police at once.

Collocations with visibly:
A few common collocations with visibly are: visibly shaken, visibly better, and visibly upset.
He was visibly shaken by the sight of blood after the accident so it’s no wonder that he can’t get over it.
After the experimental treatment, my mother is visibly better so we all hope that she will recover soon.
I don’t know what he said to her, but she was visibly upset after the meeting.

Incorrect spelling, explanation: visibly has a rather easy spelling, which corresponds to its pronunciation. Nevertheless, it is often misspelled as visably. It is probably the consequence of the fact that a more popular ending is able instead of ibly. However, in the case of this word, the only correct spelling is visibly.