Loaded: transitive verb. Past tense of load, or describes currently being in a state of having a load.
Something is loaded if it is under load, or doing work. A CPU is loaded if there are processes running. A spring is loaded if it is compressed. An electrical circuit is loaded if it has a resistive load attached to it.
An alternate definition of loaded is when something has significant or necessary removable or consumable parts installed. For instance, a firearm is loaded if it has a round in the chamber. A brake caliper is loaded if the brake pads are installed. Similarly, a vehicle is loaded when it has been filled with cargo or passengers.
A person is loaded if they are intoxicated. This is similar to the second definition, immediately above. This term applies to any kind of intoxication, though it is most commonly used to describe being drunk (Due to alcohol.)