It's called an Intergalactic collision or Interacting Galaxy. Where a galaxy is consumed, or more correctly "merges" is called galactic cannibalism.
By definition the question is incorrect. There are not only 2 galaxies in our universe, but billions. Each galaxy is a different size and is made up of millions or stars and planets. Our galaxy is called the Milky-Way, and our closest neighbouring galaxy is called the Andromeda galaxy.
Getting smaller is waning. Getting larger is waxing.
They are called aftershocks, or tremors.
They are called aftershocks, or tremors.
It's the fanciful, sensationalist, attention-grabbing term coined by some reporter, to describe the process when one galaxy collides with another galaxy, merging the two into one giant, irregular galaxy.
The smaller objects which are built to represent the larger objects are called Model
A galaxy is larger by far.
When larger jobs are broken down into smaller tasks, that is called specialization.
You would have to get the larger sizes cuppler with a reducer to the smaller size and then join it together
A tributary
Galaxy
The colonization of a smaller nation for a larger nation's profit is typically referred to as imperialism.