Global traveller detained by more insignificant society lawmongers (12)

'lawmongers' is the definition.
(pettifogger can informally mean a lawyer)

'global traveller detained by more insignificant society' is the wordplay.
'global traveller' becomes 'Fogg' (Phileas Fogg from Around the World in Eighty Days).
'detained by' means one lot of letters goes inside another (I've seen this in other clues).
'more insignificant' becomes 'pettier' (petty means insignificant or unimportant).
'society' becomes 's' (common abbreviation in names of organisations).
'fogg' going within 'pettier' is 'pettifogger'.
'pettifogger'+'s'='PETTIFOGGERS'