subscript
noun [ C or U ] uk/ˈsʌb.skrɪpt/ us/ˈsʌb.skrɪpt/
下标，添标
a word, letter, number, or symbol written or printed just below another word, letter, number, or symbol, usually in a smaller size
Format the figure one in superscript and the figure three in subscript. 图一用上标格式，图三用下标格式。
The subscripts s and m denote respectively quantities downstream and upstream of the shock. 下标s和m分别表示激波下游和上游的量。
subscript figures 下标数字
Compare: superscript