loggerhead noun. 
['lɒgǝhɛd] L16.[Prob. from LOGGER noun2 + HEAD noun.]1.  A stupid person. 
arch. L16.2.  A head out of proportion to the body; a large or thick head. 
colloq. L16.3.  a. In full 
loggerhead turtle. A large-headed sea turtle, 
Caretta caretta, of warm seas worldwide. 
M17.b. In full 
loggerhead kingbird. A W. Indian kingbird, 
Tyrannus caudifasciatus. 
M17.c. Any of various large-headed fishes, such as the bullhead. 
dial. L17.d. In full 
loggerhead shrike. A shrike, 
Lanius ludovicianus, of the southern US and Mexico. 
E19.e. Any of various large moths. 
dial. M19.4.  An iron instrument with a long handle and a ball at the end heated for melting pitch etc. 
L17.5.  In 
pl. (treated as 
sing.). Knapweed. 
dial. E19.6.  A rounded wooden upright near the stern of a whaling boat to which a turn of the line may be caught. 
M19.Phrases: 
at loggerheads disagreeing or disputing (
with).
 ■   loggerheaded adjective (a) stupid; 
(b) (esp. of an animal) having a large head: 
L16.  [TahlilGaran] English Dictionary ▲