IPA: /ˈsiːd.lɪŋ/
KK: /ˈsidlɪŋ/
A young plant that has just grown from a seed.
The gardener carefully watered the seedling every day to help it grow.
Seedling → It is formed from "seed" (from Old English *sǣd*, meaning the reproductive part of a plant) and "-ling" (a diminutive suffix indicating something small or young). The word "seedling" refers to a young plant that has grown from a seed.
Think of a small 'seed' that has just started to grow — that's what a 'seedling' is, a young plant from a seed.