Breakdown of Само собой.
Questions & Answers about Само собой.
Literally, it means something like by itself or of itself.
But as a fixed expression, it usually means of course, naturally, goes without saying, or that’s obvious. So the literal meaning is not the one you usually translate word-for-word in normal conversation.
It is a complete and very common expression.
Historically and semantically, it is closely related to the longer phrase Само собой разумеется, which means it goes without saying or it is understood naturally. In modern speech, people often shorten it to just Само собой.
So even though it may look incomplete to a learner, native speakers understand it as a full idiomatic reply or comment.
Само is the neuter form of сам.
In this expression, the phrase is impersonal. It does not refer to a specific masculine or feminine noun. Russian often uses the neuter in set expressions when the idea is general or abstract.
So you should learn Само собой as a fixed phrase, not as something you usually change for gender.