significant digit

noun any digit of a number that is known with certainty; any digit of a number beginning with the leftmost nonzero digit and ending with the rightmost nonzero digit (or a zero considered to be the exact value)
significant figure; significant digit.
 he calculated the answer to four significant figures
WordNet

noun any digit of a number that is known with certainty; any digit of a number beginning with the leftmost nonzero digit and ending with the rightmost nonzero digit (or a zero considered to be the exact value)
significant figure; significant digit.
 he calculated the answer to four significant figures
WordNet

noun any digit of a number that is known with certainty; any digit of a number beginning with the leftmost nonzero digit and ending with the rightmost nonzero digit (or a zero considered to be the exact value)
significant figure; significant digit.
 he calculated the answer to four significant figures
WordNet
 (Arith.), the figures which remain to any number, or decimal fraction, after the ciphers at the right or left are canceled. Thus, the significant figures of 25,000, or of .0025, are 25.
Webster 1913
significant other

noun a person (not necessarily a spouse) with whom you cohabit and share a longterm sexual relationship
spousal equivalent; spouse equivalent; domestic partner.
WordNet
Sharpen your Skills with the Masters
"Rowling never met an adverb she didn't like."
Stephen King on J.K Rowling's excessive use of adverbs.
Fear not the Adverb Hell!