rostrum

views updated Jun 11 2018

ros·trum / ˈrästrəm; ˈrô-/ • n. (pl. ros·tra / ˈrästrə; ˈrô-/ or ros·trums) 1. a raised platform on which a person stands to make a public speech, receive an award or medal, play music, or conduct an orchestra. ∎  a similar platform for supporting a movie or television camera.2. chiefly Zool. a beaklike projection, esp. a stiff snout or anterior prolongation of the head in an insect, crustacean, or cetacean.DERIVATIVES: ros·trate / ˈräsˌtrāt; ˈrôˌstrāt/ adj. (in sense 2).ORIGIN: mid 16th cent.: from Latin, literally ‘beak’ (from rodere ‘gnaw’). The word was originally used (at first in the plural rostra) to denote part of the Forum in Rome, which was decorated with the beaks of captured galleys, and was used as a platform for public speakers.

rostrum

views updated Jun 27 2018

rostrum
1. A forward projection or extension of the snout (e.g. of a fish). The typical profile of an oceanic shark reveals a massive rostrum projecting well forward and above the low-slung mouth.

2. The snout-like extension to the head that forms the specialized piercing and sucking mouth-parts of the Hemiptera (true bugs). The stylets are sheathed by the labrum, which forms a jointed tube closed dorsally at the base by the labrum. In feeding, only the stylets enter the tissues of the host plant or prey.

3. In prawns, a spine-like extension of the cephalothorax.

4. (guard) In Belemnitida, a massive deposit of fibrous calcite.

5. In Brachiopoda, a beak-like process on the umbo.

rostrum

views updated May 08 2018

rostrum
1. (guard) A massive deposit of fibrous calcite which makes up part of a belemnite (Belemnitida) skeleton.

2. In a brachiopod (Brachiopoda), a beak-like process formed by the drawing out of the umbo.

rostrum

views updated Jun 08 2018

rostrum.
1. Bow section of an Antique Roman warship, resembling a beak, ornamented with an animal-head, buckler, or helmet (acrostolium), forming the projections on columnae rostrata.

2. Daïs or platform raised above the general level.

rostrum

views updated May 23 2018

rostrum platform for public speakers in ancient Rome, adorned with beaks of captured ships XVI; beak of a galley XVII; platform, stage, pulpit XVIII. — L. rōstrum beak, snout, etc., f. rōdere gnaw.

rostrum

views updated May 14 2018

rostrum (ros-trŭm) n. (pl. rostra) (in anatomy) a beaklike projection, such as that on the sphenoid bone.
rostral adj.