This is the American spelling of favouritism — not a different word, and not a weaker one. It still means treating one person or group better than others in a way that is not fair. British English keeps the u (favouritism, favourite, favour); American English drops it (favoritism, favorite, favor). You will meet the same split in color/colour and neighbor/neighbour. In Taiwan both spellings show up, because some exams and textbooks lean British while American news, films, and websites do not. Neither spelling is “more correct”; you match the reader in front of you. If your teacher or test is British-style, keep the u. People stretch the word, too: a parent who always lets one child choose the show may be accused of favoritism, and that can sound almost playful. At work, in school grading, or in government, the same word feels heavier — closer to cheating, not just liking someone more.