first-grade
UK/'fɜ:stɡr'eɪd/US/'fɜ:stɡr'eɪd/
Definitions
adj.
Of the highest quality or rank; (US) of the first year of school.
一级的，甲级的；（美）小学一年级的。
Root Breakdown
Root-derivedfirst + grade (a rank/level) = of the first rank. In AmE 'grade' is also a school year, so 'first-grade' can describe the first year of elementary school.
Root gress still carries 64 more wordsExample Sentences
- 1.
This is first-grade lumber, free of knots.