SISTERS

noun

1. A daughter of the same parents as another person; a female sibling.
2. A female member of a religious order; especially one devoted to more active service; (informally) a nun.
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.

verb

1. To strengthen (a supporting beam) by fastening a second beam alongside it.
2. To be sister to; to resemble closely.