Loggerhead \Log"ger*head`\, n. [Log + head.]

1. A blockhead; a dunce; a numskull. --Shak. Milton.

2. A spherical mass of iron, with a long handle, used to heat tar.

3. (Naut.) An upright piece of round timber, in a whaleboat, over which a turn of the line is taken when it is running out too fast. --Ham. Nav. Encyc.

4. (Zo["o]l.) A very large marine turtle (Thalassochelys caretta, or caouana), common in the warmer parts of the Atlantic Ocean, from Brazil to Cape Cod; -- called also logger-headed turtle.

5. (Zo["o]l.) An American shrike (Lanius Ludovicianus), similar to the butcher bird, but smaller. See Shrike.

To be at loggerheads, To fall to loggerheads, or To go to loggerheads, to quarrel; to be at strife. --L' Estrange.

Source: Webster's Revised Unabridged Dictionary (1913)