Here's a breakdown:
* Wrinkle: This refers to the distortion or "wrinkling" of the fabric of space-time.
* Time: This refers to the fourth dimension, alongside the three spatial dimensions (length, width, and height).
In the book, the characters, guided by Mrs. Whatsit, Mrs. Who, and Mrs. Which, travel through time and space by manipulating the fabric of the universe. They literally "wrinkle" the fabric of space-time, creating shortcuts and allowing them to reach their destination faster than would be possible through conventional means.
The title is also a metaphor for the challenges the characters face. The journey through time and space reflects the challenges they encounter in their quest to save Meg's father and combat the forces of darkness. The "wrinkles" represent the unexpected turns, twists, and difficulties that they face along the way.
Therefore, the title "A Wrinkle in Time" is both a literal and figurative description of the journey the characters take, encapsulating the themes of adventure, discovery, and the power of love and courage.