a hole dug in the ground to hold the end of an upright post
posthole in American English
(ˈpoustˌhoul)
noun
1.
a hole dug in the earth for setting in the end of a post, as for a fence
2. Archaeology
an excavated hole showing by its shape and by the remains of wood or other debris that it was once filled by a post
Word origin
[1695–1705; post1 + hole]This word is first recorded in the period 1695–1705. Other words that entered Englishat around the same time include: caisson, exponential, piston, telescopic, vector