The term "AHD" has multiple meanings depending on the context. Here are the different meanings of AHD based on the search results:

• Alveolar Hydatid Disease: A medical condition that affects the lungs and liver.
• American Hospital Directory: A website that provides data, statistics, and analytics about more than 7,000 hospitals nationwide.
• Analog High Definition: A video surveillance standard that allows the camera to send an HD signal over a standard coax or RCA cable.
• Australian Height Datum: The height of a point above mean sea level in Australia.

Therefore, the meaning of AHD depends on the context in which it is used.