What does crenation mean?
Crenation describes a notched, scalloped, or wavy edge—the state of being marked with small rounded indentations. The word appears most often in the life sciences. In botany, it characterises leaf margins edged with shallow, rounded teeth, helping distinguish closely related plant species. In biology and medicine, crenation refers to the shrivelling of a cell, classically a red blood cell placed in a hypertonic (overly salty) solution: water exits the cell by osmosis, it contracts, and its membrane puckers into a scalloped outline. The phenomenon illustrates osmotic pressure vividly enough that it is a staple of school laboratory work, which makes the term familiar to students of biology long before they meet it elsewhere. Derived from the Latin 'crena', meaning notch, crenation carries no emotional connotation; it is a precise, descriptive term valued for its accuracy in scientific writing rather than for any rhetorical force.
nounA rounded notch or scalloped indentation along an edge, or the state of having such a notched margin. In biology and medicine, it refers especially to the shrivelled, scalloped appearance of a cell—most commonly a red blood cell—that has lost water in a hypertonic solution.
- The condition of a cell (especially a red blood cell) becoming shrunken and scalloped due to water loss in a hypertonic environment.
- A rounded notch or scalloped indentation along the margin of a structure, such as a leaf edge in botany.
"Under the microscope, the red blood cells showed clear crenation after exposure to the salt solution."
"Placing red blood cells in a concentrated saline solution causes rapid crenation as water leaves the cells."
"The botanist identified the species by the fine crenation along its leaf margins."
The plural is uncommon but legitimate when referring to multiple individual notches or instances of crenation.
"Fine crenations lined the entire margin of the leaf."
Your red blood cells literally sprout little spikes when you get dehydrated—and biologists have a word for that look: crenation.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of crenation
Crenation derives from the Latin noun 'crena', meaning a notch or incision, itself of uncertain earlier origin. English adopted it via New Latin scientific usage, with related adjective forms such as 'crenate' appearing in botanical description from around the early nineteenth century. It shares this root with 'crenel', the square notch in a battlemented wall, whose derivative 'crenellation' describes castle parapets—an elegant reminder that the same idea of a notched edge spans both fortifications and leaf margins.
Related word forms
How crenation is actually used
A technical term used chiefly in biology, medicine, and botany; rare in everyday speech. In haematology it typically describes the spiky, contracted appearance of erythrocytes in hypertonic media, sometimes contrasted with true echinocyte formation.
Easily confused with crenation
Cremation is the burning of a body to ashes, while crenation is the formation of a notched or scalloped edge on a structure such as a leaf margin or a shrunken cell.