upside /ˈʌpˌsaɪd/noun 3preposition 1forms 1phrases 2 noun3 •The highest or uppermost side or portion of something. •(figurative) the good thing about a situation that also has problemsThe only upside of being over 35 is that you don't get raped as much. — 2013 •An upward tendency, especially in a financial market etc. preposition1 •(informal) On the top of.Ruth Ann clenched her hand around the hairbrush and felt like smacking Ashley upside the head with it. She knew better than to talk that way. — 2002 formsupsides Phrases with upside fuck someone upside downTo give someone a bad scolding. turn upside downTo flip over; to rotate top to bottom.