From Longman Dictionary of Contemporary Englishsistersis‧ter /ˈsɪstə $ -ər/ ●●● S1 W1 noun [countable] 1 SSFFAMILYa girl or woman who has the same parents as you → brother, half-sister, step-sister Janet and Abby are sisters. He has two sisters and a brother.older/big sister My older sister is a nurse.younger/little sister Where’s your little sister? She’s my twin sister.2 → sister paper/publication/company etc3 (also Sister)RRC a nun Good morning, Sister Mary.4 British English (also Sister)MN a nurse in charge of a hospital ward the ward sister I’m feeling a bit better today, Sister.5 SSFRIENDLYa word used by women to talk about other women and to show that they have feelings of friendship and support towards them We appeal to our sisters all over the world to stand by us.6 American English spokenTALK TO somebodyWOMAN a way of talking to or about an African-American woman, used especially by African AmericansCOLLOCATIONSadjectivesan older sister (also an elder sister especially British English)He had two older sisters, Karen and Jacqueline.a big sister (=an older sister)She misses her big sister dreadfully.a younger sisterMary showed a lot of aggressive behaviour towards her younger sister.a little/kid sister (=a younger sister)She was very fond of her little sister.a baby sister (=a sister who is still a baby)He wanted a baby sister.a twin sisterHe is devoted to his twin sister.a half-sister (=a sister with only one parent the same as yours)She doesn't see her half-sister very often.
Examples from the Corpus
sister• Sister Mary Margaret• I thought she would be sympathetic because she's a sister.• They assist their parents in feeding their new younger brothers and sisters and in defending them from predators such as snakes.• She was drinking coffee, and her sister asked if Bernstein would like some.• She and her sister Pam were both Miss West Virginia.• Penelope, standing behind her sister, wished that a more exciting hotel would have been chosen.• They married in 1910 and she came to live at West park, where Father was farming with his sister, Hannah.• Its sister mission in Tumacacori was built of adobe and has crumbled under the weight of the years.• We have to support our sisters in southern Africa.• There are secret pains between the two sisters, but the movie never illuminates their problems.• I've a lot of respect for your sister.twin sister• I had a twin sister I might never have known about.• You - both of you - must have know that a twin sister could be the saving of her life!• Mr Goldring said that after Becky died her twin sister Katie was brought into the hospital purely for observation.• Muhammad Reza was timid, even gentle and self-questioning, quite unlike his twin sister, Ashraf.• Sheer panic: Accused describes the barn fire that killed twin sisters.• My twin sister is a nurse and I suppose all the blood and thunder of things took me a different way.• How, then, do we explore the geology of our twin sister planet?• Maryellen is the twin sister of a woman Manny had gone out with over ten years ago in New York.ward sister• The amount of time spent by ward sisters on teaching varies considerably.• She had the right academic approach to nursing to make a first-class tutor, but not ward sister.• Indeed, in some hospitals, joint appointments of ward sister and teacher have been introduced.• It might have been the ward sister or the staff nurse.• I eventually tracked down the ward sister, who was wrestling with an intravenous drip that had collapsed.• Philip stood helplessly while she talked to the ward sister and exerted her considerable authority to get the doctor called immediately.• The ward sister and trained staff on the other hand may have forgotten the small incidents which cause anxiety in the learner.• The ward sister has up-to-date information, for example, the social worker's reports or changes in treatment.Origin sister Old English sweostor 