Learner's definition of SIMPLE
[or more simple; most simple]
1 : not hard to understand or do
a simple task
The solution to the problem was relatively simple.
The answer is really quite simple.
a simple [=straightforward] explanation
a simple recipe
There are three simple steps/rules to follow.
The camera is simple to use.
The directions seem simple enough. [=seem fairly simple]
Just press the button. It is as simple as that. = Just press the button. It is that simple.
Don't go into too much detail in the report. Just keep it simple and to the point.
2 : having few parts : not complex or fancy
The engine has a simple [=basic] design.
a simple machine
The melody is very simple.
She wore a simple [=plain, unadorned] black dress.
We don't want to spend a lot of money on the party, so we're keeping it simple. [=we're not having an extravagant party]
3 always used before a noun : not special or unusual : ordinary
I'm a simple farmer just trying to make a living.
He enjoys the simple pleasure of spending time with his wife and kids after work.
Relaxing on the beach and watching the sunset is one of life's simple pleasures.
4 always used before a noun : complete and total — used for emphasis
I watch what I eat, but the simple truth is that I can't resist chocolate.
The simple fact is that he did not study for the exam.
I don't want to go for the simple reason that [=because] I'm very tired.
5 grammar, of a sentence : having only one main clause and no additional clauses 6 old-fashioned : not very intelligent
the simple life
◊ If you live the simple life, you do not own many things or use many modern machines and you usually live in the countryside.