\s*a Unicode whitespace character, repeated any number of times
\ba Unicode word boundary
x+the literal x (12010 / 1708 / 7816) (case sensitive), repeated at least once
\ba Unicode word boundary
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