Here's why and some options:
* No direct translation: "Pendrive" is a relatively modern technology, and Tamil doesn't have a direct equivalent word.
* Descriptive phrases: You could use descriptive phrases like:
* "நினைவகக் குச்சி" (Ninaivaka kutti): This translates to "memory stick."
* "கையடக்க நினைவகக் கருவி" (Kaiyatakka ninaivaka karuvi): This means "portable memory device."
* Borrowed term: The term "பேன் ட்ரைவ்" (Pen drive) is often used, which is simply the English term adopted into Tamil.
Ultimately, the best word depends on the context and your target audience. You might need to explain what a "pendrive" is if using a descriptive phrase.