plus/minus sign

noun

: the sign ± used to indicate a quantity (such as 2 in "the square root of 4 is ±2") taking on both an algebraically positive value and its negative and to indicate a plus or minus quantity (such as 4 in "the population age was 30 ± 4 years")

called also plus/minus symbol

Word History

First Known Use

1971, in the meaning defined above

Kids Definition

plus/minus sign

noun

: the sign ± used to mean that a quantity (as 2 in "the square root of 4 is ± 2") takes on both a positive and a negative value or to indicate a plus or minus quantity (as 5 in "the scale was accurate to ± 5 grams")

called also plus/minus symbol