Unsisterly is an antonym of sisterlike.
As adjectives the difference between unsisterly and sisterlike
is that unsisterly is not sisterly; not befitting a sister while sisterlike is resembling a sister or some aspect of one.
sisterlike
English
Adjective
(
en adjective)
Resembling a sister or some aspect of one.
Synonyms
* sisterly
Antonyms
* unsisterlike
* unsisterly