contrivance
A clever thing or plan made to solve a problem.
A contrivance is something cleverly made or invented to solve a problem, often in an ingenious or unexpected way. When you need to reach a high shelf and stack books to stand on, you've created a contrivance. When someone builds a Rube Goldberg machine with dominoes, ramps, and pulleys just to turn off a light switch, that elaborate contraption is a contrivance.
The word can describe physical inventions or clever schemes and plans. A spy might use a contrivance to send secret messages. An author might use plot contrivances to make unlikely events happen in a story, like having two characters coincidentally meet at exactly the right moment.
Sometimes contrivance suggests something feels artificial or forced rather than natural. If a friend creates an overly complicated excuse for being late, you might see through the contrivance. A movie plot might feel contrived when events seem too convenient or unrealistic.
The related verb is contrive, which means to create or plan something cleverly. Robinson Crusoe contrived ways to survive on his island, building tools and shelter from whatever he could find. When you contrive a solution, you use creativity and resourcefulness to make something work, even with limited materials or difficult circumstances.