oaf
A clumsy, awkward person who often bumps or knocks things over.
An oaf is someone who is clumsy, awkward, and not very graceful in how they move or act. When someone bumps into furniture, knocks things over accidentally, or moves through a room like a bull in a china shop, you might call them an oaf. The word also suggests someone who isn't very thoughtful or socially aware, like a person who talks too loudly in a library or doesn't notice when they're bothering others.
Picture a large, well-meaning person who accidentally steps on your science project or spills juice all over the table while reaching for bread. They don't mean any harm, but they seem unaware of their own size and strength. That's an oafish quality.
The word carries a hint of affection sometimes, especially when describing someone who means well but just can't seem to avoid making a mess of things. You might call your brother an oaf when he trips over his own feet playing basketball, but you're not truly trying to be mean about it.
However, oaf can also be a genuine insult, suggesting someone is both clumsy and unintelligent or rude. Context matters: calling yourself an oaf after dropping your lunch tray is self-deprecating humor, but calling someone else an oaf might hurt their feelings.