The word stave has many different definitions. If used as a noun. stave refers to a wooden plank used in the construction of a building or a musical staff (symbol). If used as a verb, stave refers to breaking something by force or averting something negative. None of the previous definitions define stave's use in Charles Dickens' A Christmas Carol (although the musical staff is the closest).
Dickens use of the word stave refers to chapters in the text. This is a common concept for him given that he uses similar musical terms for other texts ("quarters" in The Chimes and "chirps" in The Cricket on the Hearth). Here are the names of the five staves in the novella.
Stave I: Marley's Ghost
Stave II: The First of the three Spirits
Stave III: The Second of the Three Spirits
Stave IV: The Last of the Spirits
Stave V: The End of It
The use of the word stave here refers to songs (in order to make the reader more aware of the relevance of the title (Christmas Carol--in reference to songs sung at Christmas time).