"oomf" means: One Of My Followers. A way to subtweet or reference someone in your following without naming them. Common on stan Twitter.. This is a fairly neutral word with no inherent risk attached. There is no real cause for parental concern; it is descriptive vocabulary rather than something dangerous. If your child uses it, context will usually make the meaning clear. A brief, curious question about where they heard it is generally enough to know whether to follow up.