off
particle
A thing that was touching or stuck to a surface comes away from it, leaving a gap.
Where the picture shows up
- Take your shoes off at the door.the picture itselfremoved from the body or a surface. The shoes were touching your feet. Now they come away.
- He fell off his bike.the picture itselfdown from a surface you were on. Your body leaves the surface it was sitting on.
- The plane took off at noon.the picture itselfleave the ground; depart. The plane separates from the ground, so a gap opens.
- Turn off the lights.picture, stretchedstop a machine or power. Like a switch breaking contact, the power is cut away.
- I'm off work tomorrow.picture, stretchednot at work; free. You are separated from your job for a while.
- The milk smells off.picture, stretchedgone bad; not right. Something has moved away from its normal, good state.
- They called off the match.picture, stretchedcancel something planned. The plan is removed, like taking it off the calendar.
- She told him off for being late.idiomcriticise someone angrily. No clear link to the picture of coming away.
Not the same as “out”
Was it on a surface or inside something? Leaving a surface is 'off'. Leaving a container or space is 'out'.
Root
Old English 'of', meaning 'away, away from'. It was just an unstressed and stressed form of the same word. Around the 1600s the stressed spelling 'off' split from 'of'. It comes from Proto-Germanic *af and relates to Latin 'ab' and Greek 'apo', meaning 'away'.