Answer: sturdier

AnswerCrossword Clue
STURDIERMore robust
STURDIERNot as fragile
STURDIERMore resolute.
STURDIERMore vigorous
STURDIERMore stalwart
STURDIERLess likely to collapse
sturdierSTURDY, strong and durable
sturdierfirmly built or constituted stout