1. Having been flattened
   - planate

1. Make flat or flatter
   "flatten a road"; "flatten your stomach with these exercises" 
2. Become flat or flatter
   "The landscape flattened"
   - flatten out 
3. Lower the pitch of (musical notes)
   - drop

See also: planar, two-dimensional

Type of: alter, change, change form, change shape, deform, form, modify, shape

Antonym: sharpen

• giant seaperch
• giant sequoia
• giant silkworm
• giant silkworm moth
• giant slalom
• giant squid
• giant star
• giant star grass
• giant stock bean
• giant sunflower
• giant taro
• giant timber bamboo
• giant tortoise
• giant water bug
• giant willowherb
• giantess
• giantism
• giaour
• giardia
• giardiasis
• gib
• gibber
• gibberellic acid
• gibberellin
• gibberish