Invariably means always or consistently happening or done.
When we say something happens invariably, we mean it's not an exception. It happens every single time without fail. Think about things that are so predictable they become boring - like rain on Mondays in a place with high humidity. People often joke about how the weather is going to be bad and grey on Monday morning. That kind of routine or pattern makes something happen invariably.
The word can also be used as an adjective, describing someone's personality or behavior. For example, "She's invariably punctual for meetings." In this case, it means that she always arrives right on time, never late. The adverb form emphasizes consistency, so when you say that something happens or is true in a certain way invariably, you're talking about a regular pattern.
In rare cases, 'invariably' can be used as an adverb to mean without exception, but this is less common than its other uses.
Every time; always, without change.
Example: He is invariably late for meetings.
