Bullshido means: Martial arts fraud, especially exaggerated or fraudulent claims regarding the biography, lineage, skills or experience of martial arts instructors.. It is informal slang, fine in casual speech but not suited to formal contexts. It is generally derogatory or offensive; worth a quiet word about how it lands on the person being described. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.