Like it sounds, a shoehorn is a tool (originally made from an animal's horn) that you use to help slide your foot into your shoe.
Now, imagine you're trying on a shoe that fits terribly, and the only way you can even fit your foot inside it is by shoving it in with the shoehorn.
To shoehorn something, or to shoehorn something in, or to shoehorn something into something else, is to shove it in awkwardly, even though it doesn't fit properly.
Part of speech:
Verb, the transitive kind: "they shoehorned this product onto consumers," "he shoehorned himself into the conversation."
Other forms: shoehorned, shoehorning
How to use it:
"Shoehorn" provides a visual metaphor that can range from funny to highly critical.
We might be literal and talk about shoehorning objects or even people into places: "an overcrowded school with children shoehorned into tiny portables," "an overstuffed suitcase tilting precariously forward, the toiletries shoehorned into the outer zipper pocket."
And often we're abstract, talking about shoehorning data, facts, images, ideas, references, information, actions, activities, events, and other bits and pieces into larger places where (and times and occasions when) they don't belong.
examples: "Low-fare passengers shoehorned into the back of the plane may not even be covering what it costs to transport them."
— Scott McCartney, Wall Street Journal, 14 February 2018
"And so the show goes, stumbling from one scene to the next with no evidence of coherence, shoehorning songs that advance neither plot nor characterization. We meet, for instance, a hellish boogeyman named Carl (Zak Risinger), who complains that his hands are too big in a song titled 'When Your Hands Are Too Big.'"
— Elisabeth Vincentelli, New York Times, 16 December 2018