This is the 146th most frequent Hebrew word.
אחרת
"Other," "another," or "different" (feminine).
In this sentence, the word "אחרת" is used as an adverb, meaning "differently."
אם נלך בדרך הזאת, נגיע אחרת מאשר בדרך השנייה.
If we take this path, we will arrive differently than on the other path.
Here, "אחרת" implies a contrary opinion or perspective, translating to "otherwise."
אני חושב שזאת הייתה שגיאה, וגם היא חושבת אחרת.
I think it was a mistake, and she thinks otherwise.
In this context, "אחרת" is used as a conjunction, meaning "otherwise."