[I7] another nitpicky performance question

Consider the following three approaches:

Understand "rusty", "rusted", "rust", "ferrous", "oxidized" as the iron bell.
Understand "rusty/rusted/rust/ferrous/oxidized" as the iron bell.

Understand "rusty/rusted/rust/ferrous/oxidized" as "[rusty]". Understand "[rusty]" as the iron bell. Understand "[rusty]" as the old nail. Understand "[rusty]" as the dicey catwalk.

Which of these approaches (if any) might potentially cause performance issues, if implemented in sufficient numbers?

In other words: do I gain (or lose) any performance by mashing lots of dictionary entries together into slash-separated tokens as often as possible? What if I converted the slash-separated tokens into bracket tokens (as in the 3rd example) and reused them wherever possible?

In other, other words: Are these tactics better saved for specific circumstances, or could they make a significant difference in performance when used across a game with thousands of dictionary entries?

The first form saves some function calls (maybe two per synonym?) so it’s marginally faster than the other two. I wouldn’t count it as a major worry.

However, if you’re thinking about the second and third approaches because they look faster, don’t bother. They’re not.