Linux Documentation – Accessing Online Man Pages from Terminal

With the risk of raising a question that might already have an answer, i would like to ask if anybody knows if and how is it possible to read man pages in my terminal for programs/apps that are not installed in my system using online sources/online tools.

I made a stackexchange and google search but found nothing about this issue.

For example man grep will raise the grep manual as expected.
On the other hand man agrep will give an error since agrep is not installed.
In order to read agrep manual i have to google agrep man pages , getting results like this : https://linux.die.net/man/1/agrep

PS: BTW it seems strange to me that http://man7.org/linux/man-pages/dir_all_alphabetic.html do not provide agrep…

I wonder if it is possible to run man agrep or similar command from my terminal (without installing agrep) and read agrep man pages in terminal as usual man works.

I don't expect all man pages of the world to be locally available; i just wonder if there is any tricky way to use man (or even other command) to search and display man pages of not installed progs without having to open browser, type keyword, search in results etc.

PS: As noticed by Kusalananda, raising web queries may lead to results not suitable for particular distro version (different versions result will pop up). So the best (in my dream) would be if there was a kind of Distro specific (Debian in my case) internal / built in command (or even a switch) that could retrieve online man pages specifically for my setup (i.e something like : man --online agrep or onlineman agrep). It seems not.