sister noun
ADJ. big, elder, older | baby, kid, little, small, wee, younger | twin | full (= sharing both parents) | half-(= sharing one parent), step-(also stepsister) (= the daughter from an earlier marriage of your stepfather or stepmother) | beloved, much-loved | dead, deceased, late | unmarried
PHRASES brother and sister Have you got any brothers and sisters? | like sisters The girls are so close, they're like sisters.
You can also check other dicts: sister (English, 中文解释 ), wordnet sense, Collins Definition