A "gainer" can refer to different things depending on the context. Here are some possible meanings based on the search results:

• Acrobatics: In the context of acrobatics, a "gainer" is a type of backflip where the person jumps forward and then flips backward.

• Food: According to Urban Dictionary, a "gainer" can also refer to a person who intentionally gains weight due to sexual stimulation. However, this is not a widely recognized definition.

• Other meanings: "Gainer" can also refer to a type of flatbread from South Asia made of lentil flour, or to a street musician or performer.

Its important to note that the term "gainer" can have different meanings depending on the context, and some of the definitions found in the search results may not be widely recognized.