"Tezza" means: The British politician Theresa May (born 1956), Home Secretary from 2010 to 2016 and Prime Minister of the United Kingdom from 2016 to 2019.. This is informal slang, common in casual speech, texting and social media, but not appropriate for school work, applications or professional settings. There is no real cause for concern in itself; it is everyday peer vocabulary. If your child uses it, a light comment about audience and register is usually enough — no need to escalate. Context, more than the word, tells you whether to follow up.