The phrase "at the door" is commonly used to indicate someone or something is outside a building's entrance or waiting to enter. There are several synonyms that can be used in place of this phrase, such as "knocking," "waiting," "outside," and "on the doorstep." Other possible options include "pending arrival," "standing by," "expecting," "approaching," and "nearby." Each of these alternatives can be handy when describing the location of someone or something, particularly in written descriptions or stories. Choosing the right synonym depends on the context, tone, and purpose of the communication, so it's essential to consider these factors carefully when making a choice.