First catch your hare(, then cook him).
((諺))取らぬタヌキの皮算用
First come, first served.
先着順,早い者勝ち
first milk
初乳
First Secretary at the Japanese Embassy
日本大使館付き一等書記官
first thing in the morning
朝一番に
First you dial “1.”
最初に1番を回してください
First, it's easy to use. Secondly, ...
第一にそれは使いやすい.第二に…
first-class passengers on the train
1等車の乗客
first-degree burns
第1度熱傷
first-night nerves
初日のあがり