Yes the medicine gabapentin is considered a painkiller.
The gabapentin medicine is prescribed by doctors to people who are experiencing pain and the taking of the gabapentin helps to get rid of the pain.
Such as someone who has an amputated toe, legs feet etc that may experience pain they may be prescribed gabapentin to help ease that pain.
The gabapentin is also sometimes prescribed for other conditions that people suffer from that cause severe pain as well.
However gabapentin is not a good medicine or painkiller to take long term as gabapentin has been shown to cause more severe health problems in the people who take the gabapentin.
So it's best to avoid gabapentin as a painkiller unless absolutely necessary as some people who do take the gabapentin say that their health started going downhill more when they were prescribed the gabapentin.