Gradle is not an ordinary English word. Then, what does it mean in Android Studio?
It's the name of a build system for Java programs. Gradle is the build system currently recommended by Google for building Android apps.
To learn more, check out the top item of this list.
I just learned about Gradle an hour ago. It reminds me of "Cradle to Grave" which I thought was a good name for Software Project Manager. After reading your question I googled it's meaning and in December 2011 the inventor said:
My original idea was to call it Cradle. The disadvantages of that name were:
not very unique
As Gradle is using Groovy for the DSL I went down the G-road and thought about calling it Gradle. Everyone I asked liked it so that became the official name. That was about 4 years ago. I’m still very happy with the name.
So from the author we can gleam the Gradle was invented in 2007.
More to the point
From wikipedia we learn:
Gradle is an open-source build automation system that builds upon the concepts of Apache Ant and Apache Maven and introduces a Groovy-based domain-specific language (DSL) instead of the XML form used by Apache Maven for declaring the project configuration.1 Gradle uses a directed acyclic graph ("DAG") to determine the order in which tasks can be run.
Gradle was designed for multi-project builds, which can grow to be quite large. It supports incremental builds by intelligently determining which parts of the build tree are up to date; any task dependent only on those parts does not need to be re-executed.
The initial plugins are primarily focused on Java,2 Groovy and Scala development and deployment, but more languages and project workflows are on the roadmap.
In computer old school terms we can say it only compiles objects that have changed in a project when some source code has changed. Thereby saving total compile time from hours to minutes.
In layman's terms we can say it's a project manager that knows all the bits and pieces required to build something.