What is considered lying in Buddhist (five) precepts? This precept is often translated as harsh speech or false speech. The meaning of this precept is often understood as not to tell lie. But how are we supposed to define "lie" in Buddhist context particularly fourth precept?

An example:
One student got kicked out from a University because of unacceptable conducts. Someone knows this and is asked by his friend what has happened to that student. 
Instead of telling his friend that student got kicked out, his answer is, that student probably already moved to other University.
The truth is, the student has committed unacceptable conducts therefore the student got kicked out.

There are many cases in life because of security reason, sensitive information, privacy, etc. we say another thing when we are asked. But is this the same as telling lie e.g. harmful food is said/declared as healthy food, counterfeit product is answered as genuine product? Is being honest the same as having wisdom?
Not providing all information, changing the subject or staying silent does not break the precept. But, marketing harmful food as healthy food or selling counterfeits as originals does break the precept.

Understanding the importance of honesty and knowing when to speak,what to speak and whom to speak are all instances of wisdom.