\ba Unicode word boundary
Negative Lookahead(?!olo|\w*olo\b) olothe literal text olo (case sensitive) \w*a Unicode word character, repeated any number of times
olothe literal text olo (case sensitive) \ba Unicode word boundary
\w*a Unicode word character, repeated any number of times
olothe literal text olo (case sensitive) \w*a Unicode word character, repeated any number of times
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string