Diactine, dī-ak′tin, adj. having two rays.—Also Diac′tinal.

Diactinic, dī-ak-tin′ik, adj. capable of transmitting the actinic rays of the sun.

Diadelphous, dī-a-del′fus, adj. grouped together in two sets—of the stamens of plants.—n. Dī′adelph. [Formed from Gr. di-, double, and adelphos, brother.]

Diadem, dī′a-dem, n. a band or fillet worn round the head as a badge of royalty: a crown: royalty.—adj. Dī′ademed, wearing a diadem.—Diadem spider, the common garden spider—from its markings. [O. Fr. diademe—L. diadema—Gr. diadēmadia, round, and deein, to bind.]

Diadexis, dī-a-dek′sis, n. (path.) the transformation of one disease into another, differing both in location and character. [Gr.]

Diadochi, dī-ad′o-kī, n. the generals who became monarchs of the various kingdoms (Syria, Egypt, &c.) into which the empire of Alexander the Great split after his death (323 B.C.). [Gr. diadochos, succeeding, a successor; diadechesthai, to succeed.]

Diadrom, dī′a-drom, n. a course or passing: a vibration. [Gr.]

Diæresis, Dieresis, dī-ēr′e-sis, n. a mark (¨) placed over one of two vowels to show that each is to be pronounced separately, as aërial:—pl. Diær′eses, Dier′eses. [Gr.,—dia, apart, hairein, to take.]

Diaglyph, dī′a-glif, n. an intaglio. [Gr.]

Diagnosis, dī-ag-nō′sis, n. the distinguishing a disease by means of its symptoms: a brief description:—pl. Diagnō′ses.—v.t. Dī′agnose, to ascertain from symptoms, as a disease.—adj. Dīagnos′tic, distinguishing: characteristic.—n. that by which anything is known: a symptom.—n.pl. Diagnos′tics, the branch of medicine to which the skill in noting and interpreting symptoms belongs. [Gr., dia, between, gnōsisgnōnai, to know.]