- ortho-
[ortho- 词源字典]
- before vowels orth-, word-forming element meaning "straight, upright, rectangular, regular; true, correct, proper," now mostly in scientific and technical compounds, from Greek ortho-, stem of orthos "straight, true, correct, regular," from PIE *eredh- "high" (cognates: Sanskrit urdhvah "high, lofty, steep," Latin arduus "high, steep," Old Irish ard "high").[ortho- etymology, ortho- origin, 英语词源]