Definition of "oct-" in English

prefix

1. Form of octa- or octo- used before a vowel.

2. (chemistry) Used for the digit eight to form systematic element names of elements whose existence has been predicted, and which have not yet been given a trivial name.

   • un- (“1”) + bi- (“2”) + oct- (“8”) + -ium (element suffix) → unbioctium (“element 128”)