"NA" is commonly used in various contexts, including in medical fields to indicate "not applicable" or "not available." However, there are several synonyms to use in place of "NA" in different scenarios to enhance your vocabulary: "absent," "missing," "unavailable," "inapplicable," "nonexistent," "omitted," "void," "null," "deficient," "lacking," and "voided." Using synonyms helps avoid redundancy and makes writing more personalized. In conclusion, knowing synonyms for "NA" can add more novelty to your writing and conversations and make you stand out as a versatile communicator.