Undervalue

v. t. [imp. & p. p. UNDERVALUED; p. pr. & vb. n. UNDERVALUING.]

1. To value, rate, or estimate below the real worth.
2. To esteem lightly; to treat as of little worth; to despise; to hold in mean estimation.

In comparison of the discharge of my duties, I undervalued all designs of authority. Atterbury. I writ not this with the least intention to undervalue the other parts of poetry. Dryden.