Yes, "frail" does not have a suffix. It is a standalone word.
The elderly woman moved slowly, her frail frame barely able to carry the weight of her years.
"Frail" comes from the Latin word fragilis, "breakable", via Old French frele. Fragilis in turn comes from the verb frangere, "to break". Believe it or not, frangere and "break" (and thus "frail" and "breakable") are related: they ultimately both come from the Proto-Indo-European root bhreg.
The suffix of "undoing" is "-ing."
The suffix of "moon" is "-oon".
The suffix is -er, meaning "one who campaigns."
The elderly woman moved slowly, her frail frame barely able to carry the weight of her years.
Frail male (frail male)
After her illness, the old woman appeared frail and weak as she slowly walked down the hallway.
He was very frail, frail meaning weak.
The frail old woman needed assistance walking up the stairs.
Frail-weak Sick-ill
Joe Frail was born in 1869.
Frail - song - was created in 1987.
Frail Women was created in 1932.
Frail as Breath was created in 2005-09.
Frail male.
There is one syllable in the word frail