I. in·val·id (ˈ)in|valə̇d, ənˈv- adjective
Etymology: Latin invalidus not strong, infirm, weak, inadequate, from in- in- (I) + validus strong — more at valid
1.
a. : being without foundation in fact or truth : indefensible , unjustified
this argument … is invalid on two counts — Monsanto Magazine
now that rockets can escape gravity it is invalid to say that what goes up must come down
b. : lacking in effectiveness : inadequate , weak
acceptance of the new method was a tacit admission that the old technique was invalid and inferior
2.
[Medieval Latin invalidus, from Latin]
: being without legal force or effect
declared the wills technically invalid because of some legal flaw — Robert Graves
II. invalid transitive verb
( -ed/-ing/-s )
archaic : invalidate
III. in·va·lid ˈinvələ̇d, Brit |invə|lēd adjective
Etymology: Latin & French; French invalide, from Latin invalidus
1.
a. : suffering from disease or disability : sickly , disabled
hired a nurse to care for his invalid mother
b. : of, relating, or suited to one that is sick
invalid chair
the whole family lived on invalid fare, on custards and broths and arrowroot pudding — Jean Stafford
2. : being in poor condition : weakened, unsound
reminding me that, if my chimney was allowed to stand in that invalid condition, my policy of insurance would be void — Herman Melville
IV. in·va·lid ˈinvələ̇d; Brit ˈinvəˌlēd also ˌinvəˈlēd noun
( -s )
: one that is sickly or disabled
arranged a bed table for the invalid — Eden Phillpotts
an exaggeration to assume that France is a chronic economic invalid — Paul Johnson
specifically archaic : a member of the armed forces who has become unfit for active duty by illness or injury
his garrison at present consists of a few hundreds of invalids — Tobias Smollett
V. in·va·lid ˈinvələ̇d, esp before a syllable-increasing suffix -ˌlid; Brit |invə|lēd verb
( -ed/-ing/-s )
transitive verb
1. : to make sickly or disabled
because of a bone ailment, has been invalided since childhood — Sat. Eve. Post
2. : to classify as sick or disabled and remove from active duty
of the 185 firemen … sixty were invalided home because of smoke poisoning, burns, or exhaustion — Joseph Millard
specifically : to release from military service because of illness or injury
invalided out of the Norfolk Yeomanry with rheumatic fever — Saturday Review
received three bullets through the body, and was due to be invalided home — Joyce Cary
intransitive verb
archaic
1. : to become an invalid
cannot conceal from myself that I am invaliding — R.W.Sibthorp
2. : to become released from active duty because of disability
the conscripts … invalid at an inexplicable rate — Spectator