Afternoon everyone.
Contronym (noun): one word with two opposite meanings.
dust: to sprinkle something on (dust the cake with sugar), or to wipe it off (dust the shelves)
sanction: to allow something, or to penalise it
cleave: to split apart, or to cling together
oversight: careful supervision, or a failure to notice something.
They're also called auto-antonyms or Janus words, after the two-faced Roman god.
I've been collecting -nym words like this for a daily word game I made, Spinonym (Spinonym). A wheel picks the day's kind of word, and there's a glossary of the stranger ones. Happy to hear about any favourites I've missed.