To bilk someone means to cheat them out of money or possessions through clever tricks or deception. When con artists bilk elderly people out of their savings, they use elaborate lies and fake schemes to steal from them. A dishonest contractor might bilk homeowners by charging for work they never completed, or by using cheap materials while billing for expensive ones.

The word suggests something more calculated than simple stealing. Someone who bilks you doesn't just grab your wallet and run: they gain your trust first, then use that trust against you. A crooked accountant might bilk a company by slowly moving money into fake accounts over many years. A scam artist might bilk investors by convincing them to put money into a business that doesn't really exist.

When someone gets bilked, they usually don't realize it right away. By the time they discover the deception, the bilker has often disappeared with the money. That's what makes bilking particularly sneaky: it combines lying, manipulation, and theft all at once. The word can also apply to smaller situations, like when someone bilks a vending machine by using a trick to get free snacks, though it most often describes serious fraud involving significant amounts of money.