Here are a few possibilities:
1. "Crazy" (Common):
- Sign for "crazy": This sign is made by touching your temple with your index finger and moving it in a circular motion. It's a common way to express "crazy" or "loco" in a general sense.
2. "Insane" (More severe):
- Sign for "insane": This sign is made by touching your forehead with your index finger and making a small, rapid circular motion. It implies a higher level of mental instability than "crazy."
3. "Stupid" (Negative connotation):
- Sign for "stupid": This sign is made by tapping your forehead with your index finger. It conveys a sense of foolishness or lack of intelligence.
4. "Funny" (Humorous):
- Sign for "funny": This sign is made by bringing your index finger and thumb together to form a circle and rotating it near your cheek. It suggests something silly or amusing.
5. "Not right" (Mental instability):
- Sign for "not right": This sign is made by tilting your head slightly to the side and making a circular motion with your index finger near your temple. It can express a more subtle form of "loco" or mental instability.
Context is key: To choose the most appropriate sign, you need to consider the specific situation and the intended meaning of "loco."
Remember: ASL is a visual language, so it's important to observe the signs and facial expressions of native signers to understand the full nuance of each sign.