There are far more concepts than there are terms to describe them. This leads to the use of a single term to signify more than one concept. Such terms are known as homonyms. For instance, the term "table" is used in conversations in business about whether or not to discuss a topic. Someone may say "Let's table that". Unfortunately, some people think this means "Let's take that topic off the table", while others think it means "Let's put that on the table". The differences in interpretation are geographic, with the British thinking it means one thing and the Americans another. It makes for pretty interesting conference calls on transatlantic projects. I have managed to forget which side thinks of it which way.
So homonyms exist, and we have to deal with them. But what about technicial terms? Technical terms are specific to very specialized domains. It might be thought that the narrowness of the domain would itself guarantee that a technical term would have only one definition. But there is no guarantee of this. An example I often come across is "data model" in the realm of data management. To some this means an artifact for the design of a database produced by utilizing a standard symbology. To others it means the actual design of a physical database. The first means an artifact produced by a tool like ERwin. The second means the underlying design of an actual physical database, and certainly not a design artifact.
This is very confusing, and can cause a lot of problems in communication. Working with technical language is very difficult to begin with. Having technical terms with more than one definition makes things much worse.
If it is possible to set up a technical vocabulary, or to reform a technical vocabulary, then it is possible to ensure that one technical term has one definition. This is part of the work that terminologists do.
Yet, even if a technical vocabulary is set up by terminologists, they cannot control its usage. If a technical term starts to have marketing value it will be used to signify things that may be the same as the original concept, or a different concept, or no concept at all. We call this "hype". If a general community cannot fully understand the concept signified by a technical term, they will use the term to mean something they think they understand, as in the example of "data model" above.
To answer the question originally posed, a technical term should only have one definition, at least within a particular technical domain. However, we have no way to ensure a technical term will always signify the same concept.
So what is the conclusion? If we want to master technical terms we need to understand what they are intended to signify, and be alert to detecting when they are used to signify other concepts. A big piece of this is having a glossary of terms with adequate techncial definitions.