upon my word

English

(dated) Believe my words; I swear.
- 1924, William Somerset Maugham, Salvatore:
  Salvatore had enormous hands, like legs of mutton, coarse and hard from constant toil, but when he bathed his children, holding them so tenderly, drying them with delicate care; upon my word they were like flowers.
(dated) Expressing surprise.
Synonym: my word
- 1871, Mary Elizabeth Braddon, Fenton's Quest:
  'Well, upon my word,' exclaimed the father, taking the pipe from his mouth, and staring aghast at his daughter in a stupor of indignant surprise, 'you're a pretty article; you're a nice piece of goods for a man to bring up and waste his substance upon […]