In economics it is described as "the value of the next-highest-valued alternative use of that resource" (Library of Economics). Or easier explained, the cost of choosing one thing over another.
In communications it means, what happens when we choose to say or communicate something over something else, or to tell someone instead of someone else.
That is why it is important to be aware of the cost of opportunity when communicating with our stakeholders, customers, colleagues and bosses in this fast-paced world with time scarcity and where the opportunities of getting our point across are very rare.
Thus the importance of having a mind scheme of what we want or need to discuss about and how to lead the conversation so to achieve the best outcome.
Here are some easy tips on how to choose the right words:
1) Write down all the ideas or worries in your mind;
2) Organize them in groups depending on their key subject;
3) Number them in order of priority, and make yourself a little note on what needs more explaining;
4) Try to organize them in a way you can jump from one issue to the next (make sure you start with what is most important in case you run out of time);
5) If the communication is spoken: Reharse a couple of times so you feel comfortable with the set of words you are using and make sure the speech has a clear goal and it develops smoothly;
If the communication is written: Start drafting the letter/writing, put it to rest and read it the next morning to make sure it still sounds and says what it needs to.
As an extra tip, I would recommend you to always choose positive expressions over negative, and make sure you choose the right moment to communicate for it is going to be half of your success!