frontier   (Sound)

The frontier has 3 Senses.

• frontier
• 辺塞, フロンティア, 辺隅, 辺疆, 辺境
• a wilderness at the edge of a settled area of a country; "the individualism of the frontier in Andrew Jackson's day"
• ある土地の、居住地の端にある荒れ地

• frontier
• 国境
• an international boundary or the area (often fortified) immediately inside the boundary
• 国境線またはその境のすぐ内側の地帯（しばしば防壁のある）

• frontier
• 最前線
• an undeveloped field of study; a topic inviting research and development; "he worked at the frontier of brain science"
• 未開発の研究分野