It's the lateral sense of the definition. This thread isn't filled with characters who still have a strong sense of ambition, some of them, like Sasuke, have ended their goals.
Yes sasuke done with his old ambition(revolution),but his ambition now is to protect Konoha his daugher, probably wife too hah and to kill evils... that's why he travels and searchs criminals and kills them. So sasuke is still ambitiouse and has new goals...
Itachis ambition is no differnt from him,Minato(who sicrificrd himself his wife and sealed evil nine tails inside his newborn son),Tobirama who also sicrificed himself to save Danzo,Sarutobi,Kagami and others,Hiruzen,Kakashi who died against pain Just bc Of intel and choji... and there are many others.... i dont say anything about Naruto..... the thing that Itachi killed his parents doesnt make him more ambitiouse then others....they have same ambition... some just suffered more for this ambition.