angle strain
Strain due to a departure in bond angle from 'normal' values. The term is often used in the context of non-aromatic cyclic compounds in which the internal angles differ from the regular tetrahedral angle of 109° 28′; in this sense angle strain is also known as Baeyer strain.
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2198 (