Complicated means made of many parts and hard to follow. A complicated process, it is complicated, unnecessarily complicated.
Complicated and complex overlap, and the useful distinction is that complex describes something with many interacting parts and complicated describes something difficult to understand or deal with. It is complicated is a standard way of declining to explain something. Note complicate, the verb; complication, which in medicine means a further problem arising from the first; and that a complicated relationship is a well-worn phrase for one nobody wants to describe.
1adjectivecomplicatedMade of many parts and hard to follow.
“The rules are complicated and almost nobody has read them.”
complicated is a quality of difficulty.