Thoral
(Tho"ral) a. [L. torus a couch, bed.] Of or pertaining to a bed. [R.]
Thorax
(Tho"rax) n. [L., fr. Gr. .]
1. (Anat.) The part of the trunk between the neck and the abdomen, containing that part of the body
cavity the walls of which are supported by the dorsal vertebræ, the ribs, and the sternum, and which the
heart and lungs are situated; the chest.
In mammals the thoracic cavity is completely separated from the abdominal by the diaphragm, but in
birds and many reptiles the separation is incomplete, while in other reptiles, and in amphibians and fishes,
there is no marked separation and no true thorax.
2. (Zoöl.) (a) The middle region of the body of an insect, or that region which bears the legs and wings.
It is composed of three united somites, each of which is composed of several distinct parts. See Illust.
in Appendix. and Illust. of Coleoptera. (b) The second, or middle, region of the body of a crustacean,
arachnid, or other articulate animal. In the case of decapod Crustacea, some writers include under the
term thorax only the three segments bearing the maxillipeds; others include also the five segments bearing
the legs. See Illust. in Appendix.
3. (Antiq.) A breastplate, cuirass, or corselet; especially, the breastplate worn by the ancient Greeks.
Thoria
(Tho"ri*a) n. [NL. See Thorite.] (Chem.) A rare white earthy substance, consisting of the oxide
of thorium; — formerly called also thorina.
Thoric
(Thor"ic) a. (Chem.) Of or pertaining to thorium; designating the compounds of thorium.
Thorite
(Tho"rite) n. [So called by Berzelius from the Scandinavian god Thor. See Thor.] (Min.) A
mineral of a brown to black color, or, as in the variety orangite, orange-yellow. It is essentially a silicate
of thorium.
Thorium
(Tho"ri*um) n. [NL. See Thorite.] (Chem.) A metallic element found in certain rare minerals,
as thorite, pyrochlore, monazite, etc., and isolated as an infusible gray metallic powder which burns in
the air and forms thoria; — formerly called also thorinum. Symbol Th. Atomic weight 232.0.
Thorn
(Thorn) n. [AS. þorn; akin to OS. & OFries. thorn, D. doorn, G. dorn, Dan. torn, Sw. törne,
Icel. þorn, Goth. þaúrnus; cf. Pol. tarn, Russ. tern' the blackthorn, ternie thorns, Skr. t&rsdot&nsdota
grass, blade of grass. &radic53.]
1. A hard and sharp-pointed projection from a woody stem; usually, a branch so transformed; a spine.
2. (Bot.) Any shrub or small tree which bears thorns; especially, any species of the genus Cratægus, as
the hawthorn, whitethorn, cockspur thorn.
3. Fig.: That which pricks or annoys as a thorn; anything troublesome; trouble; care.
There was given to me a thorn in the flesh, the messenger of Satan to buffet me.
2 Cor. xii. 7.
The guilt of empire, all its thorns and cares,
Be only mine.
Southern. 4. The name of the Anglo-Saxon letter capital form . It was used to represent both of the sounds of
English th, as in thin, then. So called because it was the initial letter of thorn, a spine.
Thorn apple (Bot.), Jamestown weed. — Thorn broom (Bot.), a shrub that produces thorns. —
Thorn hedge, a hedge of thorn-bearing trees or bushes. — Thorn devil. (Zoöl.) See Moloch, 2. —
Thorn hopper (Zoöl.), a tree hopper (Thelia cratægi) which lives on the thorn bush, apple tree, and allied
trees.
