honorarium
noun /ˌɒnəˈreəriəm/
  /ˌɑːnəˈreriəm/
(plural honoraria 
 (formal) /ˌɒnəˈreəriə/
  /ˌɑːnəˈreriə/
)- a payment made for somebody’s professional services Use an, not a, before honorarium.Word Originmid 17th cent.: from Latin, denoting a gift made when a person is admitted to public office, from honorarius, from honor ‘honour’.