biconditional
noun
bi·con·di·tion·al ˌbī-kən-ˈdish-nəl 
-ˈdi-shə-
: a relation between two propositions that is true only when both propositions are simultaneously true or false see Truth Table
Word History
First Known Use
1940, in the meaning defined above
- harks (to)
- harks back
- harks back (to)
- harks back to
- harks to
- harl
- Harlan
- Harlan's hawk
- harle
- Harlech
- Harlem
- Harlem blue
- harlemite
- harlemites
- harlems
- harlequin
- harlequin beetle
- harlequin bug
- harlequin cabbage bug
- harlequin duck
- harlequin ladybird
- harlequin opal
- harlequin pigeon
- harlequin quail
- harlequin snake