Invariably means every single time, without exception. Invariably late, invariably ends the same way, invariably true.
It is an absolute claim and is nearly always an exaggeration in speech, which is part of its charm. Used strictly it means without variation, and mathematics and science reserve it for that.
1adverbinvariablyEvery single time, without exception.
“Whenever we plan a picnic, it invariably rains.”
invariably is a manner.
Also accepted in games: always
From invariable + -ly.
Etymology from Wiktionary, CC BY-SA