* Simple: The scientist's idea of a perpetual motion machine seemed chimerical at best.
* Descriptive: The artist's chimerical sculptures blended elements of human, animal, and machine, creating a surreal and unsettling effect.
* Figurative: Her hopes for a quick and painless solution to the complex problem were chimerical, a fantasy that would never come to fruition.
* Formal: The philosopher argued that the pursuit of absolute happiness was a chimerical endeavor, as happiness is inherently fleeting and subjective.
The best way to use "chimerical" in a sentence depends on the specific context and the desired tone.
Let me know if you'd like more examples!