Final answer:
The abbreviation 'OS' is often misused to refer to the left ear but actually stands for the left eye; the correct term for the left ear is 'AS'.
Step-by-step explanation:
The abbreviation that is used verbally to refer to the left ear and is on the JCAHO Do Not Use list is 'OS'. 'OS' stands for 'oculus sinister' which is Latin for 'left eye' and is sometimes mistakenly used instead of 'AS'. 'AS' stands for 'auris sinistra', the correct term for 'left ear'. The Joint Commission’s "Do Not Use" list advises against the use of potentially ambiguous abbreviations, acronyms, and symbols in medical documentation to prevent miscommunication and errors in patient care.