ortho-
/ˈɔːθəʊ/combining form
1
- straight; rectangular; upright表示“直的”; “直角的”, “正交的”; “直立的”：
orthodontics.
1.1
- right; correct表示“对的”, “正确的”：
orthoepy.
2
3
- Chemistry denoting a compound from which a meta-compound is formed by dehydration【化】表示“正”; “原”：
orthophosphoric acid.
词源
from Greek orthos 'straight, right'.