be as good as gold

be as good as gold

1. To be obedient and well-behaved. Sure, I'll baby-sit Cindy's kids tonight—they're as good as gold every time I watch them.
2. To be authentic and legitimate. According to the curator, this painting is as good as gold.
See also: gold, good
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
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