The correct spelling of lamp+post is lamppost.
Lamppost is a compound noun, formed by two nouns, lamp, and post.
A compound noun can be a closed, opened, or hyphenated word. In this case, lamppost is written as a closed word. Generally, compound nouns formed by two nouns are written as a single word.
It is spelled with double p because we don't drop the final p corresponding to the noun lamp.
Another example of a compound noun formed by noun + noun with a double consonant is:
ear+ring ⇒ earring
You can learn more about compound nouns in the link below:
https://brainly.com/question/11184742
