RegEx: Boundary Assertions III

Write a regular expression that ensures the word "end" is inside of another word (e.g. "bending"). Non-word characters such as !, ?, etc. cannot be boundaries.

Examples

"The end of the story." ➞ false
"Endings are pointless." ➞ false
"Let's send!" ➞ false
"We viewed the rendering at the end." ➞ false
"Sometimes bending the rules is good." ➞ true

Notes

• You cannot use \w, *, . or + in your expressions.
• You don't need to write a function, just the pattern.
• The expression should be case-insensitive and should check all occurences of "end".