> "Sopping to" makes no sense in English.
English definitions are descriptive instead of prescriptive. In this context, an English dictionary will describe how words are used in practice rather than prescribing how they should be used in theory. It stands to reason that English dictionaries are likely to have holes in their definitions, especially in cases where words are used in novel ways.
It helps to keep in mind that a person’s written or spoken English is correct if other English speakers -- some, not all -- correctly interpret the words as having the communicator’s intended meaning. This particular case is just someone verbing with a noun, which is a common practice in informal English.