to not have or not have enough of something that is needed or wanted
Many rural villages lack clean drinking water.
The report shows that small businesses often lack access to affordable loans.
✦ From Middle English laken “to be wanting”, from Old Norse laka “to diminish”.
to make something become black or very dark, or to become that way itself
Smoke from the candle began to black the ceiling.
The silver quickly blacked when it was left in the air.
