1.  petit bourgeois(n = noun.person) - a member of the lower middle class;
is a kind of bourgeois, burgher
is a member of petit bourgeois, petite bourgeoisie, petty bourgeoisie

2.  petit bourgeois(n = noun.group) petite bourgeoisie, petty bourgeoisie - lower middle class (shopkeepers and clerical staff etc.);
is a kind of bourgeoisie, middle class

petit bourgeois, n. (pl. petits bourgeois pronunc. same) a member of the lower middle classes.

Etymology:
F

bourgeois, petit, petit dejeuner, petit four, petit juror, petit jury, petit larceny, petit mal, petit mal epilepsy, petit point