1. Aspen with a narrow crown; eastern North America
   - Canadian aspen, bigtooth aspen, bigtoothed aspen, big-toothed aspen, large-toothed aspen, large tooth aspen

Type of: aspen

• onanist
• once
• once again
• once and for all
• once in a blue moon
• once in a while
• once more
• once upon a time
• once-over
• onchocerciasis
• oncidium
• Oncidium papilio
• Oncidium papilio kramerianum
• oncogene
• oncologic
• oncological
• oncologist
• oncology
• oncoming
• Oncorhynchus
• Oncorhynchus keta
• Oncorhynchus kisutch
• Oncorhynchus nerka
• Oncorhynchus tshawytscha
• oncost