secondborn

noun 0.803

firstborn

noun 0.755

baby of the family

noun 0.745

youngest

noun 0.733

firstling

noun 0.643

little brother

noun 0.619

eldest

noun 0.618

newborn

noun 0.613

younger

noun 0.609

runt of the litter

noun 0.599

only child

noun 0.572

stillborn

noun 0.572

kid brother

noun 0.563

latecomer

noun 0.563

oldest

noun 0.561

little sister

noun 0.557

little one

noun 0.553

single child

noun 0.551

youngin

noun 0.551

youngling

noun 0.543

birth

noun 0.540

late bloomer

noun 0.531

youngblood

noun 0.529

younger sister

noun 0.528

youngster

noun 0.528

baby boy

noun 0.527

natural son

noun 0.525

unborn

noun 0.524

underclassman

noun 0.522

live birth

noun 0.515

young blood

noun 0.513

last

noun 0.511

primogenitor

noun 0.511

youngness

noun 0.506

young gun

noun 0.504

afterbirth

noun 0.503

little boy

noun 0.503

young

noun 0.502

grandbaby

noun 0.502