a thick-headed or stupid person; blockhead.

loggerhead turtle.

loggerhead shrike.

a ball or bulb of iron with a long handle, used, after being heated, to melt tar, heat liquids, etc.

a rounded post, in the stern of a whaleboat, around which the harpoon line is passed.

a circular inkwell having a broad, flat base. ?

at loggerheads

engaged in a disagreement or dispute; quarreling

They were at loggerheads over the distribution of funds.