underdrag

From under- +‎ drag.

underdrag (usually uncountable, plural underdrags)

1. (geology) The tensile stress exerted by an overthrust rock mass upon overlying rocks which themselves are not under compressive thrusting stress and therefore tend to be stretched and broken by normal faulting.

underdrag (third-person singular simple present underdrags, present participle underdragging, simple past and past participle underdragged)

1. (transitive) To exert pull on the underside of (something).
2. (intransitive) To undergo a pull from the underside.

• undergrad