From Longman Dictionary of Contemporary Englishoverlieo‧ver‧lie /ˌəʊvəˈlaɪ $ ˌoʊvər-/ verb (past tense overlay /-ˈleɪ/, past participle overlain /-ˈleɪn/, present participle overlying) [transitive] technical COVERto lie over something Clay overlies chalk in the southern mountains.→ See Verb table