shell

(redirected from tilde)
Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.

shell

(shel),
An outer covering.
Farlex Partner Medical Dictionary © Farlex 2012

shell

(shel)
An outer covering.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

shell

any hard outer covering, such as the carapace of turtles and tortoises, the exoskeleton of crustaceans, the calcareous plates of echinoderms, the outermost membranes of an egg, the skeleton of Foraminifera or the mantle secretions of molluscs.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

impression, eye

A negative form or replica of the anterior part of the eye. A substance with rapid gelling properties is held in contact with the eye until gelled. This impression (or mould) is then used in the preparation of a positive model called a cast (or casting) of the anterior part of the eye: it is made by filling the impression with a material containing a plaster of Paris base which hardens to artificial stone. Using this cast a shell of a scleral contact lens is produced with optimum shape of the back surface. Syn. impression; impression moulding; mould; ocular impression.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
While expressing dismay over the development, Aliyu Tilde who himself has decamped to the opposition SDP said that, 'But I am saddened, all the same, given that both are friends of mine.
QUAKE 3 ARENA PCCDROM FIRST,pull down the console window by pressing the (tilde) key it's to the left of 1 on the top of your keyboard.Then type in\devmapx -where x is the map name, for example Q3DM3.
However, in the choice of its candidates, I hope it will support only those that cherish its fundamental values - good guys like Dr Tilde. I am so good that I should be going for the presidency.
I can make a loaf at home from the starter which I rescue from the dead as often as I can remember to feed it, but Tilde's sourdough bread is the real thing.
* Excel quick formats: General--Ctrl+Shift+~(tilde); Currency--Ctrl+Shift+$; Percentage--Ctrl+ Shift+%; Date (d, m, y)--Ctrl+Shift+#.