Learner's definition of APPLICATION
1 a : a formal and usually written request for something (such as a job, admission to a school, a loan, etc.)
We've made an application for certification. [=we have applied to be certified]
Our loan application has been approved/denied.
Anyone interested in running for office must file/submit an application by August 1st.
[noncount] b [count] : a document that is used to make a formal request for something
2 : the act of applying something: such as a : the act of putting something on a surface, a part of the body, etc.
The application of heat often helps sore muscles.
I prefer using the lotion because of its ease of application. [=because it is easy to apply]
Repeated application of fertilizer will help the grass become green and healthy.
[count] b : the use of an idea, method, law, etc., in a particular situation or for a particular purpose
Strict application of the rules is necessary in this case.
the application of new information
learning about the creative application [=use] of new technology
c [noncount] : the use of a word, name, etc., to describe someone or something
He teaches his students about the practical applications [=uses] of technology.
I think it is a fair application of the law.
applications of science to everyday life
3 : the ability to be used for practical purposes
4 [count], computers : a computer program that performs a particular task (such as word processing)
— called also "chiefly US, informal"app
5 [noncount], formal : effort made to work hard in order to complete something successfully