(n.) An abbreviation standing for the name of an element and consisting of the initial letter of the Latin or New Latin name, or sometimes of the initial letter with a following one; as, C for carbon, Na for sodium (Natrium), Fe for iron (Ferrum), Sn for tin (Stannum), Sb for antimony (Stibium), etc. See the list of names and symbols under Element.
SYMBOL
Meaning of SYMBOL in English
Webster's English dictionary. Английский словарь Webster. 2012