Etymology: alphabetic + numeric, numerical
1. consisting of both letters and numbers and often other symbols (as punctuation marks and mathematical symbols)
Example: an alphanumeric code; also being a character in an alphanumeric system 2. capable of using or displaying alphanumeric characters • alphanumerically adverb • alphanumerics noun plural
A decimal digit or a letter (upper or lower case). Typically, "letters" means only English letters (ASCII A-Z plus a-z) but it may also include non-English letters in the Roman alphabet, e.g., e-acute, c-cedilla, the thorn letter, and so on. Perversely, it may also include the underscore character in some contexts.