What does acini mean?
Acini is the plural of acinus, a term from anatomy and histology describing the smallest functional units of certain glands. Each acinus is a tiny, berry-shaped cluster of secretory cells arranged around a central opening, and together they resemble miniature bunches of grapes — which is precisely what the Latin word means. Acini are found in exocrine glands such as the pancreas and salivary glands, where their cells produce digestive enzymes and saliva, and the term is also applied to the pulmonary acinus, the gas-exchanging unit of the lung. Because the word belongs almost entirely to scientific and medical writing, general readers encounter it mainly in histology textbooks, pathology reports, or articles on glandular disease. Its related adjective, acinar, appears frequently in phrases like 'acinar cells'. Knowing acini offers a vivid example of how anatomists borrow everyday imagery — here, fruit — to name the body's microscopic structures.
nounAcini is the plural of acinus, denoting the small, berry-shaped terminal clusters of secretory cells found in glands such as the pancreas, salivary glands, and lungs.
- Plural of acinus: any of the small, sac-like clusters of secretory cells at the ends of ducts in glands such as the pancreas and salivary glands.
- In respiratory anatomy, the functional unit of the lung consisting of a terminal bronchiole and its associated alveoli.
"Under the microscope, the pancreatic acini appeared as dense clusters of secretory cells surrounding a central lumen."
"The histology slide revealed damaged acini in the submandibular gland."
"In emphysema, the architecture of the pulmonary acini is progressively destroyed."
Acini is itself the standard plural of acinus, following the Latin second-declension pattern (-us → -i). It should not be given an additional English plural.
"The salivary acini secrete the initial components of saliva."
The word literally means 'grapes' in Latin — because under a microscope, these tiny gland clusters look exactly like bunches of berries.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acini
Acini comes directly from the Latin acinus, meaning 'grape' or 'berry', which anatomists adopted because the clustered secretory units of glands resemble tiny bunches of fruit. The Latin term itself derives from the Greek akis, meaning 'point', reflecting the pointed shape of a grape or berry. English borrowed the word in its Latinized plural form during the development of modern microscopy and anatomy, and it shares this ancient root with words such as acute and acuity, which trace back to the same Indo-European notion of sharpness.
Related word forms
How acini is actually used
Strictly technical and scientific in register, appearing almost exclusively in anatomy, histology, pathology, and medical literature. It is always used as a plural; the singular is acinus. The adjective form is acinar (as in 'acinar cells').
Easily confused with acini
Acinus is the singular form referring to one berry-shaped unit, while acini is its plural referring to multiple such units.