1. (v.t.)overturn to cause to turn over on the side, face, or back.
2. overturn to destroy the power of; overthrow.
3. (v.i.)overturn to turn over; capsize.
4. (n.)overturn the act of overturning.
5. overturn the state of being overturned.
6. overturn the thorough circulation of water and nutrients brought about in a lake by the action of wind in the spring and fall.
Etymology: (1175–1225)
Definition of 'overturn'
Princeton's WordNet
1. (noun)upset, overturn, turnover the act of upsetting something "he was badly bruised by the upset of his sled at a high speed"
2. (verb)overturn, upset an improbable and unexpected victory "the biggest upset since David beat Goliath"
3. (verb)overturn, turn over, tip over, tump over turn from an upright or normal position "The big vase overturned"; "The canoe tumped over"
4. (verb)overturn, tip over, turn over, upset, knock over, bowl over, tump over cause to overturn from an upright or normal position "The cat knocked over the flower vase"; "the clumsy customer turned over the vase"; "he tumped over his beer"
5. (verb)overrule, overturn, override, overthrow, reverse rule against "The Republicans were overruled when the House voted on the bill"
6. (verb)overthrow, subvert, overturn, bring down cause the downfall of; of rulers "The Czar was overthrown"; "subvert the ruling class"
7. (verb)revoke, annul, lift, countermand, reverse, repeal, overturn, rescind, vacate cancel officially "He revoked the ban on smoking"; "lift an embargo"; "vacate a death sentence"
8. (verb)revolutionize, revolutionise, overturn change radically "E-mail revolutionized communication in academe"
Definitions of overturn 
Afrikaans: omkeer, omslaan
Arabic: يَقْلِبُ رأسا على عَقْب
Bulgarian: обръщам
Brazilian: virar(-se)
Czech: převrátit (se)
German: umkippen
Danish: vælte
Greek: αναποδογυρίζω
Spanish: volcar, dar una vuelta de
Estonian: kummuli ajama, kummuli mi
Farsi: واژگون کردن
Finnish: kaataa
French: faire chavirer, (se) reto
Hebrew: לַהֲפוֹך
Hindi: पलट जाना
Croatian: prevrnuti se
Hungarian: felborít
Indonesian: terbalik
Icelandic: velta, hvolfa
Italian: rovesciare, rovesciarsi
Japanese: ひっくり返す
Korean: 전복하다
Lithuanian: ap(si)versti
Latvian: apgāzt
Malay: terbalik
Dutch: (doen) omslaan
Norwegian: velte, kantre
Polish: przewrócić (się)
Persian: واژگون کردن
Pashto: سرچپه كول
Portuguese: virar(-se)
Romanian: a (se) răsturna
Russian: опрокидывать(ся)
Slovak: prevrátiť (sa)
Slovenian: prevrniti
Serbian: prevrnuti se
Swedish: välta [omkull]
Thai: คว่ำลง
Turkish: devirmek
Taiwanese: 使翻過來，推翻
Ukrainian: перекидати(ся)
Urdu: پلٹ دينا
Vietnamese: lật đổ
Chinese: 使翻倒，推翻
