1. 未成熟的：unflattering 准确的 | unfledged 未成熟的 | unfolding model 开展模式
2. 未生羽毛的：unflattenedroll 理想刚性辊 | unfledged 未生羽毛的 | unflutedshaftofcolumn 无槽立柱 无槽柱身
3. 羽毛未丰的：unflared 无喇叭口的 | unfledged 羽毛未丰的 | unfledgedunformed 未充分发达的
4. 羽毛未丰的/未充分发达的/未成熟的：unflared /无喇叭口的/ | unfledged /羽毛未丰的/未充分发达的/未成熟的/ | unflinching /不畏惧的/不退缩的/不畏缩的/坚定不移/
adj
1. young and inexperienced
e.g. a fledgling enterprise
a fledgling skier
an unfledged lawyer
2. (of an arrow) not equipped with feathers
e.g. shot an unfledged arrow
Synonym: fledgeless unvaned
3. (of birds) not yet having developed feathers
e.g. a small unfledged sparrow on the window sill
Synonym: immature