Regular expression to match a line that doesn't contain a word?

I know it’s possible to match a word and then reverse the matches using other tools (e.g. grep -v). However, I’d like to know if it’s possible to match lines that don’t contain a specific word (e.g. hede) using a regular expression.

Input:

hoho
hihi
haha
hede

Code:

grep "<Regex for 'doesn't contain hede'>" input

Desired output:

hoho
hihi
haha