The rule for the order of joining word roots at beginning a term is?

There isn't a single, universal rule for the order of joining word roots at the beginning of a term. It depends on the specific roots and the context of the word. However, here are some general guidelines and factors to consider:

1. Meaning:

* Order of Significance: Often, the root that carries the most significant meaning comes first. For example, in "biochemistry," "bio" refers to life, which is a broader concept than "chemistry."

* Logical Flow: Sometimes, the order reflects a logical sequence. For example, "cardiovascular" refers to the heart (cardio) and blood vessels (vascular) – a logical flow of the circulatory system.

2. Etymology:

* Historical Origin: The order of roots might be influenced by their historical origins and how they have been combined in past usage.

* Greek vs. Latin: Words derived from Greek roots often have the Greek root first, followed by a Latin root. For example, "hydrocephalic" (water + head).

3. Specific Fields:

* Scientific Disciplines: Different fields of study might have specific conventions. In medicine, for example, the root indicating the body part often comes first.

* Technical Jargon: Some fields have developed unique combinations of roots, where the order might be more arbitrary but well-established within that field.

4. Exceptions:

* Common Usage: Over time, some words defy the "rules" and simply become established in common usage with a specific order.

* Meaning and Clarity: The ultimate goal is to create a clear and understandable term. If one order is more logical or intuitive, that might override other considerations.

In summary, there isn't a one-size-fits-all answer. Consider the meaning, etymology, specific field, and common usage to determine the most appropriate order of word roots.