- Transdeletion pyramid
A transdeletion pyramid (also called a transaddition pyramid or word pyramid when inverted) is a logological term for the triangular representation of a list of words in which each one is a scrambled form of the above word without one letter.
This seventeen-letter transdeletion pyramid, made of inferred words in an Unabridged
Merriam-Webster dictionary, can be found in Ross Eckler's book "Making the Alphabet Dance":
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