• (RP) IPA: /ˈtɜːn ˈtɜːtəl/
• (GA) IPA: /ˈtɝn ˈtɝtəl/, [-ɾəl]

turn turtle

1. (intransitive) Especially of a boat#Noun|boat or ship#Noun|ship, or some other vehicle: to turn#Verb|turn upside down.

   Synonyms: turtle

   • 1848, [James Fenimore Cooper], chapter VI, in Jack Tier; or The Florida Reef. [...] In Two Volumes, volume I, New York, N.Y.: Published by Burgess, Stringer & Co., OCLC 318436778 ↗, page 157 ↗:

     This brig is American—the schooner alongside is a Spaniard, that turned turtle in a tornado, about six-and-thirty hours since, and on which we have been hard at work trying to raise her, since the gale which succeeded the tornado has blown its pipe out.

2. (intransitive, figuratively) To fail; to go belly up.
3. (intransitive, surfing) To roll#Verb|roll upside down with one's surfboard (usually a longboard) to allow a wave#Noun|wave, especially a wave that has already break#Verb|broken, to pass over.
4. (intransitive, historical) To capture#Verb|capture a turtle by turning it onto its back#Noun|back.

• turtling