Meaning : Assign too low a value to.
Example :
Don't underestimate the value of this heirloom-you may sell it at a good price.
Synonyms : underestimate
Assign too high a value to.
You are overestimating the value of your old car.Meaning : Esteem lightly.
Meaning : Lose in value.
Example :
The dollar depreciated again.
Synonyms : depreciate, devaluate, devalue