deyḱ-₂
“to show, point out, pronounce solemnly”Source of Latin dīcere, English diction, predict, verdict
Root for showing or declaring, yielding Latin dīcere (to say) and English diction, verdict, predict.
Discussion
The PIE root *deyḱ- (to show, to point out, to pronounce solemnly) produced one of the most institutionally consequential word families in the Western languages — connecting the physical gesture of pointing to the abstract domains of speech, law, number, and education.
Latin dīcere (to say, to declare — originally "to point out") is the central reflex: diction (the manner of pointing out words), dictionary (a collection of pointed-out words), dictate (to say authoritatively), predict (prae-dīcere, to say beforehand), verdict (vērum + dictum, a true saying), contradict (to say against), and benediction (bene-dīcere, a good saying — a blessing). The connection to *weḱ- (the ordinary speech root, see also *sengʷʰ- for singing) reveals that PIE distinguished pointing-speech from casual speech.
The legal family is especially rich: Latin iūdex (ius + dic-, "one who points out the law") gave English judge, judicial, and prejudice. Latin indicāre (to point to) gave indicate, index, and the medical term indication.
Latin digitus (finger — the pointing instrument) gave English digit and digital — making the digital revolution etymologically a finger-revolution, named after the PIE gesture of pointing. Compare *ḱeh₂p- for grasping and *h₂eḱ- for sharpness — different hand-related roots in the PIE vocabulary.
Greek deiknymi (δείκνυμι, to show) gave paradigm (paradeigma, a pattern shown alongside) and the deictic pronouns of grammar. Sanskrit diś- (to point, to direct) confirms the Indo-Iranian reflex, with diś- meaning "direction, quarter of the sky" — that which is pointed toward.