Legionnaire's rhymes with:
legionnaires, legionnaires, legionnaires, legionnaires, legionnaires, airfares, americares, armchairs, backstairs, bankshares, daycares, delaware's, fiduciares, forebears, healthcare's, housewares, legionnaires, markair's, medicare's, nightmares, software's, somewheres, tenncare's, thoroughfares, wheelchairs
Legionnaire's sounds like:
legionaries, legionnaires, lexmark