unusual or unexpected, often making you feel curious, surprised, or slightly worried
A strange humming sound came from the old refrigerator late at night.
The movie had a strange ending that nobody in the audience expected.
✦ From Middle English straunge, from Old French estrange, from Latin extrāneus meaning ‘external, foreign’.
not familiar or known to you; new and different in a way you have not experienced before
Everything looked strange on her first morning in the foreign city.
The toddler hid behind his mother when he saw the strange man at the door.
more unusual or surprising than something else
Things got even stranger when the lights turned blue.
The story became stranger with each chapter.
✦ Comparative form of the adjective strange.
a person you do not know
A stranger asked me for directions on the street.
Children are taught not to talk to strangers.
✦ From Old French estrangeor, from estrange (“foreign, unknown”).
someone who is not familiar with a place, group, or situation
Being a stranger in a new city can be exciting and scary.
As a stranger to their customs, he watched politely.
✦ Extension of the basic meaning 'unknown person' to include unfamiliarity with environments or experiences.