Forced into a position or situation where, under normal circumstances, wouldn't have fit or belonged otherwise.
Much like the device the term was named after, it is awkwardly insisting something to be where it shouldn't.
The producer insisted the writers shoe horned a romantic sub-plot in what was supposed to just be a horror-themed crime drama.
"There was no opportunity in the conversation for Chris to talk about this thing that was only interesting to him, so he shoe-horned it into the conversation with an awkward segway."
The Goblin Horde is a gang known for arms trafficking and prostitution with known members in Clovis CA, and Amarillo TX. They are known to use the San Jauquin River to travel throughout the state. Their main rivals are the Fresno Bulldogs street gang.
Person 1: Did you hear about that shooting last night?
Person 2: Yeah I heard that the goblin horde was involved.
Person 1: Uh oh.