infirm

adj. 弱的,虚弱的,柔弱的

infertile, infertility, infest, infestation, infidel, infidelity, infield, infielder, infighting, infill, infiltrate, infiltration, infiltrator, infinite, infinitely, infinitesimal, infinitesimally, infinitive, infinitude, infinity, infirmary, infirmity, inflame, inflamed, inflammability, inflammable, inflammation, inflammatory, inflatable, inflate, inflated, inflation, inflationary, inflect, inflected, inflection (also inflexion), inflectional, inflexibility, inflexible, inflexibly,