extension
//ɪkˈsten.ʃən//
Noun
The act of extending or stretching something out, or the state of being extended
The extension of the rope allowed us to reach the other side.
An additional period of time allowed for completing something beyond the original deadline
I asked my professor for an extension on my essay deadline.
A part that is added to something to enlarge or prolong it
We built an extension to the house to add another bedroom.
An additional telephone line connected to the main line in a building
You can reach me at extension 245.
A program or file that adds specific features to a larger software application
I installed a browser extension to block ads.
The straightening of a limb or joint from a bent position
The physical therapist helped him with the extension of his knee after surgery.