The story
From B + DNA. Coined by Rosalind Franklin, for the second of two forms discovered during her X-ray crystallography experiments on DNA.
Etymology from Wiktionary, CC BY-SA 4.0.
B-DNA
Today it means: The default configuration of DNA in cells, right-hand twisting double helix with a significant size difference between major groove and minor groove, and approximately 10 base pairs per twist. Full definition →