This is the 886th most frequent Bulgarian word.
щом
"Щом" means "as soon as" or "since" in English.
Used as a conjunction to mean 'as soon as'.
Щом влезе в стаята, всички погледнаха към нея.
As soon as she entered the room, everyone looked at her.
Used as a conjunction to mean 'since' or 'if' in the context of reasoning.
Щом е станало така, трябва да е имало причина.
If it happened that way, there must have been a reason.
Used as a conjunction to mean 'if' with conditional mood.