downgrade

Từ điển WordNet v3.1 - WordNet Dictionary

I - noun

the property possessed by a slope or surface that descends
• Hypernyms:
grade

II - verb

rate lower;
lower in value or esteem (Freq. 4)
• Ant:
upgrade
• Hypernyms:
rate, rank, range, order, grade, place
• Verb Frames:
- Somebody ----s something