master / leader / teacher (in a primary school)

a title given to lawyers and notaries public in France, Belgium, and Canada

(transitive with en or dans) to become a master at something, an expert in something

(dated) associate professor; lecturer

(fencing) fencing master, fencing instructor

(archaic) dandy, coxcomb

female equivalent of maître-nageur

primary school teacher

the person in charge of the team of waiters in a restaurant or hotel / a headwaiter; major-domo

swimming instructor, swimming trainer, swimming coach / lifeguard (attendant employed to save swimmers in trouble or near drowning)