1 sister /ˈsɪstɚ/ noun
plural sisters
1 sister
plural sisters
Learner's definition of SISTER
[count] : a girl or woman who has one or both of the same parents as you
compare half sister, sister-in-law, stepsister
informal used when talking to a woman
[count] or Sister : a member of a religious community of women : nun often used as a title abbreviation Sr.
[count] : a woman who is from the same group or country as you
[count] US, informal : a black woman used especially by African-Americans
[count] chiefly British or Sister : a nurse in a hospital ward or clinic
see also weak sister
2 sister /ˈsɪstɚ/ adjective
2 sister
Learner's definition of SISTER
always used before a noun
: belonging to the same kind or group : having similar qualities or characteristics