The phrase "mother ship" usually refers to a large spacecraft or main vessel that carries smaller ships or vehicles. It's like a mother taking care of her children and keeping them safe. Full definition
Some missions require the missile launcher as players may need to take out an alien mother ship. (attackofthefanboy.com)
Everyone who has specialized in social media for the past few years needs to figure out which functional mother ship they will align their career into. (socialmediagovernance.com)
All we can do now is wait and see if this sequel can fill the massive mother ship - shaped shadow left by its predecessor. (theyoungfolks.com)