It's where about 10 guys stand in a line and a girlie goes down the line and gives them head, one by one. The guy who gets head first is running the train.
Similar to a Man train, but it only consists of African americans with afros forming a main train. black people typically have some soul in them, so it is considered a soul train.
Blackhomo 1: Daym dat soul train sure was chugging along last night.
black homo 2: mmhmmmmm(in bitchy black girl voice)
when your dog or cat, after a particularly difficult bowel movement, decides to sit on the floor, and pull it self forward using its front feet only, dragging it's asshole on the (usually) carpet to scratch the ham hocks (hemmies) off, then gets up, turns around, and sniffs the skid mark
"OMG, look, Coby's had the hershey squirts, came right inside and started riding the train."
When spoken, you emphasize the start of 'Lionel' so it sounds like 'lying'. It's when a guy lies to a virgin, saying he only packs 6 or 7 inches, when he is really packing a footlong.
Cindy believed Roger and thought he was average sized, she wound up getting a Seven Inch Lionel Train.