A Russian Slot Machine Hack Is Costing Casinos Big Time

There are three meanings listed in OED's entry for the verb slot See 'Meaning & use' for definitions, usage, and quotation evidence

Merges its props onto its immediate child

slotth The meaning of SLOT IN is to find a place for in a schedule, plan, etc How to use slot in in a sentence

slotthai walletme net a narrow, elongated depression, groove, notch, slit, or aperture, esp a narrow opening for receiving or admitting something, as a coin or a letter