the GNU version of the Collaborative International Dictionary of English
adj. Devoid of truth; dishonest; dishonest; spurious; faithless.
The Century Dictionary and Cyclopedia
Lacking truth; lacking reality; untrue.
Faithless.
Word Usage
"Senator Clinton's truthless, negative and recently most divisive 16 year Entitlement Campaign to the U.S. Presidency, has convinced me that Senator Obama is our only hope of defeating the Republicans."