The labels used with the Enneagram types are only approximations to what they actually point to. In other words, they hint at something that can't be understood by the label alone. When people take the labels too literally they may not only miss what's being pointed to but may also limit themselves in exploring and understanding the types. Take the passions of type for example.
The type 7 passion is gluttony. Literally, gluttony means excessive eating. When it's explained in terms of type 7 however, it becomes a gluttony of the mind. This can then be further explained as a desire to explore and experience the many things in life that come to an individual's mind.
The type 4 passion is envy. A literal defintion of envy would include the idea of covetousness which is desiring what someone else has. In terms of type 4 however, it's more a reminder of what they don't have or are incapable of getting. In other words, it's more about seeing what someone else has or is and how the type 4 individual is lacking in comparison.
The type 5 passion is avarice. Avarice or greed implies the desire to accumulate wealth. Type 5 is often the minimalist of the Enneagram types - the desire to get by on very little so as not to become beholden to or dependent upon others. It's more about hoarding or holding onto the resources one has. Especially when there's a sense that the world tends to take more than it gives.
If taken literally or through their commonly implied meanings, the labels used for the passions above would not only miss the point but limit one's understanding of each type. When the same labels are looked at as simply approximate pointers to an experience then the experience can be explored and the labels forgotten. The labels are only approximations to the actual experience. Discovering the actual experience being pointed to by the labels is what takes so long in truly understanding the Enneagram types. Unfortunately, often people first learning about the types are either confused by the labels (they're vague, inaccurate, etc.) or they take the labels too literally and understand the types superficially or stereotypically (type 2 is the helper, type 4 is the artist, etc.).