nom de plume 
/ˌnɑ:mdɪˈplu:m/ noun
plural noms de plume /ˌnɑ:mdɪˈplu:m/ noun /ˌnɑ:mzdɪˈplu:m/ [count] formal : a name used by a writer instead of the writer's real name : pen name
▪ He wrote under a nom de plume.
▪ He wrote under a nom de plume.
