A young shoot or bud that sprouts from a plant (stem, root, etc.). Also used figuratively (e.g., the seed of talent).
庭の桜の芽が膨らんできた。
The cherry tree buds in the garden have started to swell.
春になると、木の枝に新しい芽が次々と出る。
In spring, new shoots appear one after another on the tree branches.
彼女の文章には才能の芽を感じる。
I can sense the beginnings of talent in her writing.
The germinal disk in an egg — the part that will develop into an embryo (technical biological term).
鶏卵では、受精後に胚が発生する胚盤（芽）が重要な役割を果たす。
In chicken eggs, the germinal disk (the 'bud') plays an important role in embryo development after fertilization.