It is written wrongly. It should be 'probably'. I just googled that sentence. It is terrifying how many 'language sites' have just copied that text, without bothering to check the spelling...

In fact, this word is from text "A spark, a flint: How fire leapt to life". This text you can find in Oxford IELTS practical tests, book 1 of 9, reading passage 1.

I have never seen this word, can you make sure you spelled correctly. Maybe provide more context on how it was used.