I. | ̷ ̷ ̷ ̷| ̷ ̷ verb
Etymology: under (I) + drag
transitive verb
: to exert pull on the underside of (an overlying mass of rock)
intransitive verb
: to undergo a pull from the underside
II. ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ noun
: the combined tensile stresses exerted by an overthrust rock mass upon rocks which overlie it but are not themselves under compressive thrusting stresses and therefore tend to be stretched and broken by normal faulting