undervalue

verb ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about undervalue at Wordnik → Where our words come from →

1. Assign too low a value to.

   Don't underestimate the value of this heirloom-you may sell it at a good price

2. Esteem lightly.
3. Lose in value.

   The dollar depreciated again