1. Auxiliary: This is the most common meaning. An auxiliary is something that provides support or assistance to something else. For example:
* Auxiliary verb: A verb that helps another verb form a tense, mood, or voice (e.g., "I *am* going," "They *have* been working").
* Auxiliary power: Supplemental power supply in a system (e.g., a car's auxiliary battery).
* Auxiliary equipment: Equipment that is used in addition to the primary equipment (e.g., a computer's auxiliary hard drive).
2. Abbreviation: "Aux" can be an abbreviation for:
* Auxiliary: As mentioned above.
* Audio: Often used to indicate an audio input or output on electronic devices.
* Auxiliaries: A company or organization that provides support services.
3. Other: In some specific contexts, "aux" might have other meanings, like:
* Auxin: A plant hormone that promotes growth.
* AuX: A protein involved in cell division and DNA replication.
To understand the meaning of "aux", you need to consider the context in which it is used.
For example, in a sentence like "I need to connect my phone to the aux input," "aux" clearly refers to the audio input.