From Latin "cena".
But they don't say "The dinner" or "A dinner" in English.
So, is this a Romanian thing that I have to memorize or is there anything to understand about the sentence "Bărbatul mănâncă cina" and does "cină" mean "Dinner" or "A dinner"?
It is a specific dinner, hence the definite article. Remeber that the articles don't work the same from language to language.
I wrote it entirely correctly but on checking received "another correct solution" followed by exactly the same words (of course!)
how to say "dinner"? without the.
isn't cina def. art.?