Definitions
from The American Heritage® Dictionary of the English Language, 4th Edition
 n. Pathology An abnormal concretion in the body, usually formed of mineral salts and found in the gallbladder, kidney, or urinary bladder, for example.
 n. Dentistry See tartar.
 n. Mathematics The branch of mathematics that deals with limits and the differentiation and integration of functions of one or more variables.
 n. Mathematics A method of analysis or calculation using a special symbolic notation.
 n. Mathematics The combined mathematics of differential calculus and integral calculus.
 n. A system or method of calculation: "[a] dazzling grasp of the nation's byzantine budget calculus” ( David M. Alpern).
from Wiktionary, Creative Commons Attribution/ShareAlike License
 n. calculation, computation
 n. Any formal system in which symbolic expressions are manipulated according to fixed rules.
 n. Differential calculus and integral calculus considered as a single subject; analysis.
 n. A stony concretion that forms in a bodily organ.
 n. Deposits of calcium phosphate salts on teeth.
 n. A decisionmaking method, especially one appropriate for a specialised realm.
from the GNU version of the Collaborative International Dictionary of English
 n. Any solid concretion, formed in any part of the body, but most frequent in the organs that act as reservoirs, and in the passages connected with them
 n. A method of computation; any process of reasoning by the use of symbols; any branch of mathematics that may involve calculation.
from The Century Dictionary and Cyclopedia
 n. A small stone; a pebble.
 n. In pathology, a general term for inorganic concretions of various kinds formed in various parts of the body.
 n. In mathematics, any highly systematic method of treating a large variety of problems by the use of some peculiar system of algebraic notation.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
 n. the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
 n. a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body
 n. an incrustation that forms on the teeth and gums
Etymologies
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/ShareAlike License
Examples

Be it women, money, power or fame, the calculus is the same. drkrick says:

So Midland, plainly put, you think we should spend money on killing people for the political benefit of the Democratic party, and that anyone who objects to this calculus is a petulant child?

For the GOPer base, the calculus is the following: Tax money spent on infrastructure, running the gov't and and foreign and domestic programs?

For the GOPer base, the calculus is the following:

Another thing about calculus is that I didn't actually retain a lot of the information.
Steven Levitt, Arnold Kling  EconLog  Library of Economics and Liberty

I'm sure they'll regret putting the world's drug industry out of business, but the political calculus is pretty clear.
Quack Remedy, Arnold Kling  EconLog  Library of Economics and Liberty

I went from getting As in calculus to getting B minuses and Cs. I just couldn't concentrate.

The Governor's political calculus is clear: It is better to leave public services in tatters than impose higher taxes on corporations reaping record profits in the midst of the Great Recession.
Elissa D. Barrett: To the Righteous, Wealth Is a Greater Test Than Poverty

The concept of how one's welfare, wellbeing, or utility is personal and not easy to measure, even after the extraordinary developments in calculus and the marginal revolution in economics in the 1700s and 1800s, was understood long before Marshall's statement of the problem.

If you think that calculus is anywhere near as important to know as statistics, I believe you are at least a generation out of date.
Should Empirics Determine the Curriculum?, Arnold Kling  EconLog  Library of Economics and Liberty
jennarenn commented on the word calculus
I'll get right to work. ;)
August 11, 2007
uselessness commented on the word calculus
I'm still waiting for Life for the Kinesthetic Learner.
August 10, 2007
jennarenn commented on the word calculus
Having taken calculus in both high school and college, I think that standard curriculum really doesn't appeal to the kinesthetic modality. A life goal of mine is to write the new classic, Calculus for the Kinesthetic Learner. Actually understanding the stuff is an intermediate goal that I keep putting off. ;)
August 10, 2007