Un mondo in Italian means literally "a world" or "one world" in English.
Un bacio dall'altro lato del mondo in Italian means "A (one) kiss from the other side of the world" in English.
Un before a consonant in Italian means "a" or "one" in English.
Un bell'uomo in Italian means "a handsome man" in English.
Un attimo in Italian means "one moment" in English.
"A hallway" in English is un corridoio in Italian.
"In a relationship" in English is in un rapporto in Italian.
"An Italian mushroom" in English is un fungo italiano in Italian.
"An Italian policeman" in English means un carabiniere in Italian.
"I am an accountant" in English is Sono un ragioniere in Italian.
"I have a dream!" in English is Ho un sogno! in Italian.
"A married Italian man" in English is un italiano sposatoor un uomo sposato in Italian.
"An Italian" in English means un italiano in the masculine and un'italiana in the feminine in Italian.