On Bohol, most people speak Cebuano, or, to be more exact, the local dialect of Cebuano, called Boholano. It differs in some respect from the Cebuano spoken on Cebu. For example:
|Akoa baya ning sinilas.
|Ahoa baja ning sinilas.
|Akin itong tsinilas na ito.
|This is my slipper.
However, you will not face too much trouble making yourself understood on Bohol. Many people speak English, and almost all speak standard Cebuano as well as Tagalog.
The language nomemclature in the central Philippines is rather confusing, to say the least. As the central group of islands is called Visaya (or more properly Bisaya, as there is no V in any of the languages spoken there), some people call Cebuano 'Visayan' or 'Bisayan' (Binisaya), however this term is confusing, as this name is also applied to Hiligaynon (also known as Ilonggo), spoken on Panay and in Negros Occidental, and Waray-Waray, spoken on Leyte and Samar. The Cebuano language is spoken on Cebu, Bohol, and Siquijor and parts of Negros, Northern Mindanao, and Leyte. Adding to the confusion is that many Filipino's call these languages dialects, even though they are quite distinct in many aspects; similar to the differences between English, Dutch, and German.
Of the three main Bisayan languages, Cebuano is the most common, spoken by about a third of the Philippine population and first language to more Filipino's than any other language, including Tagalog.
As a side note, also in Borneo, there is a people calling themselves Bisaya, speaking yet another language called, you guess it, Bisaya. The historical connection is of course that most Filipino Bisayans migrated to their current homeland some 1000 years ago. In a semi-literate population (the language had its own script before the Spanish conquest), separated by seas and mountains, a language can change a lot in such a span of time, so again this language is unintelligble to Filipino Bisayans, just as much as most English speakers won't be able to make much of Anglo Saxon.
Have a look at our on-line dictionary of Philippine languages to find the meaning of Bisayan words.
If you wish to learn more about the Bisayan languages, you can visit the Bisayan Languages site.