For its grammatical function:
* Connector: This is a general term that encompasses all types of words or phrases that join elements together.
* Linker: Similar to "connector," this emphasizes the joining aspect.
* Joiner: Another word emphasizing the joining function.
For its specific type:
* Coordinating: For conjunctions that join elements of equal grammatical rank.
* Subordinating: For conjunctions that introduce a dependent clause.
* Correlative: For conjunctions that come in pairs (e.g., "both...and," "either...or").
For its semantic function:
* Relator: This highlights the relationship established between the elements being joined.
* Indicator: This emphasizes that the conjunction signals a specific type of relationship.
Ultimately, the best word depends on the specific context and the nuance you want to convey.