1. rimrock - Noun
2. rimrock - Verb
rimrock (plural rimrocks)
(geology) An outcrop of hard rock, often in the form of a cliff at the edge of a plateau, that forms the margin of a gravel deposit
rimrock (third-person singular simple present rimrocks, present participle rimrocking, simple past and past participle rimrocked)
(transitive) To drive (animals) over a cliff edge.