na-adjective, noun which may take the genitive case particle 'no', noun
premature; too early
Used to describe an action or decision that is made before the appropriate time. Often appears in the set phrase 時期尚早 (じきしょうそう), meaning 'premature' or 'too early for the time being'.
その計画を実行するのは時期尚早だ。
It is premature to carry out that plan.
結論を出すにはまだ尚早です。
It is still too early to draw a conclusion.
Compound of 尚 (しょう, 'still, yet') and 早 (そう, 'early'). The exact historical derivation is uncertain, but the combination conveys the idea of something being still too early.