Frail means so weak that you handle it gently. An old woman's wrist, a paper lantern, a voice on the telephone that has gone thin with age.
Frail belongs first to bodies, and to bodies worn down by age or illness: a frail patient, growing frail, too frail to manage the stairs. It works on objects that would give way under any real load — a frail wooden bridge, a frail little chair by the door. Figuratively it takes anything that will not hold: frail hopes, a frail truce, the frail line between order and chaos. The noun is frailty, and human frailty means weakness of character rather than of the body. Frail is not thin or small — a large person can be frail; what has gone is the strength, not the size.
1adjectivefrailWeak in body, especially through age or illness.
“Her grandmother is frail now and rarely leaves the house.”
2adjectiveeasilyEasily broken or damaged.
“The frail rope bridge swung out over the gorge.”
3adjectiveunlikelyWeak and unlikely to last.
“The frail ceasefire collapsed within a week.”
Frail and fragile are the same Latin word, fragilis, arriving twice. Frail came the slow way, through Old French fraile into Middle English frele, while fragile was lifted straight out of Latin later on. Both sit on the root behind fracture and fraction, the idea of breaking — and English quietly divided the work, so fragile goes on the parcel and frail goes on the person.
Proto-Indo-European
*bʰreg-
Latin
fragilis
Old French
fraile
Middle English
frele
English, today
frail
From Middle English frele, fraill, from Old French fraile, from Latin fragilis. Cognate to fraction, fracture, and a doublet of fragile.
Etymology from Wiktionary, CC BY-SA