Description and usage
Entrances such as doorways and gateways were rectangular. The two sides of the doorway were sometimes lined with wood, to which the hinges of the door could be attached. The doorposts were these side poles of the doorway. They also served to support the structure above the doorway.
Translation
Where technical terms for the doorframe parts do not exist, a descriptive phrase may be used; for example, in EXO 12:22, where RSV refers to “the lintel and the two doorposts,” NCV has “the sides and tops of the doorframes.”
2KI 18:16: The Hebrew word ’omnah only occurs here in Scripture, and its meaning is uncertain. The meaning of the verb root from which it is derived is “to carry, support,” and it could refer either to supporting columns for a large room or to posts that support a door opening. Most translations understand it in this second way and say “doorposts.”