Loony/ˈluːni/ Definition 1 of 3Pro Tip 1/3Colloquial Usage Use 'loony' in casual, informal conversations rather than formal writing or speech. I skipped the meeting; it sounded loony to me. Pro Tip 2/3Potentially Offensive 'Loony' can be seen as disrespectful if used to describe someone with mental health issues. It's unkind to call someone loony for their behavior. Pro Tip 3/3Humorous Tone Sometimes 'loony' is used to humorously exaggerate a strange or unconventional idea. Wearing a clown outfit to a job interview? That's loony!