あと一歩
Meanings
1
one more step; one more; another
Used when something is almost complete or just one more effort/item is needed. Often appears with verbs like 足りない, 及ばない, or in contexts of near success.
See also: 今ひとつ (いまひとつ)
We were just one step away from the championship, but we lost the final match.
We're one ingredient short, so I'll go buy more.
2
not quite; not very good; lacking
Expresses that something is slightly insufficient or falls short of expectations. Often used with ~の感がある or similar phrases.
See also: 今ひとつ (いまひとつ)
His explanation was almost convincing, but not quite.
This dish is not quite there in flavor; it needs a bit more salt.