What is the past perfect tense of the word "deceive"?
The form is had deceived
Past Perfect tense consist of Past Simple form of "have" + Past Participle of the main verb (here deceive).
Past form of have is had, since "deceive" is a regular verb its Past Simple and Past Participle forms are the same ending with "-ed" (deceived). So Past Perfect form of "deceive" is had deceived