Definition of: concretion

(kon·krē′shən) noun
1. The act of concreting; a concrete mass.
2. Geol. An aggregate of rounded masses found in sedimentary rocks and usually formed around a central core, which may be a fossil.
3. Med. a A calculus, b The abnormal joining of adjacent parts.
—con·cre·tion·ar·y (kon·krē′shən·er′ē) adjective
—con·cre′tive adjective
—con·cre′tive·ly adverb