noun

1. A daughter of the same parents as another person; a female sibling.

   “My sister is always driving me crazy.”

2. A female member of a religious order; especially one devoted to more active service; (informally) a nun.

   “Michelle left behind her bank job and became a sister at the local convent.”

3. Any butterfly in the genus Adelpha, so named for the resemblance of the dark-colored wings to the black habit traditionally worn by nuns.

Synonyms: affiliate, affiliated, charge nurse, darling, dear, lady, love, miss

verb

1. To strengthen (a supporting beam) by fastening a second beam alongside it.

   “I’m trying to correct my sagging floor by sistering the joists.”

2. To be sister to; to resemble closely.