If something isn't held back or restrained, it's unchecked, like the unchecked growth of the weeds in your neighbor's garden.

Use unchecked to describe things that are increasing or growing, especially if they're unwanted. The unchecked sprawl of a city might result in the loss of animal habitats, and your class's unchecked chatter will eventually make it impossible for you to hear the teacher when he tries to get your attention. This word comes from the verb check, "to hold or control," the way you control your opponent's king in a game of chess by putting it in check.

Definitions of unchecked

adj not restrained or controlled

“an unchecked temper”
unbridled, uncurbed, ungoverned
not subject to restraint

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