Delete by word not by character using Computers Keyboard

I have a textarea in my site. I have a word:

(e.g.)
    sampleword

I want to delete the word by words and not by character.

Output:
    ''
Incorrect Output:
    ampleword

UPDATE 1:

Below is the image of my textarea:

I want to delete the whole word using the Delete button in the keyboard.

Incorrect Output:

Correct Output:

How will I do that? What technology shall I use?