maximum

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The greatest possible quantity or degree.
• noun The greatest quantity or degree reached or recorded; the upper limit of variation.
• noun The time or period during which the highest point or degree is attained.
• noun An upper limit permitted by law or other authority.
• noun The moment when a variable star is most brilliant.
• noun The magnitude of the star at such a moment.
• noun The greatest value assumed by a function over a given interval.
• noun The largest number in a set.
• adjective Having or being the greatest quantity or the highest degree that has been or can be attained.
• adjective Of, relating to, or making up a maximum.

from The Century Dictionary.

• noun The greatest amount, quantity, or degree; the utmost extent or limit: opposed to minimum, the smallest.
• noun In mathematics, that value of a function at which it ceases to increase and begins to decrease.
• Greatest: as, the maximum velocity.

from the GNU version of the Collaborative International Dictionary of English.

• noun The greatest quantity or value attainable in a given case; or, the greatest value attained by a quantity which first increases and then begins to decrease; the highest point or degree; -- opposed to minimum.
• noun a thermometer that registers the highest degree of temperature attained in a given time, or since its last adjustment.
• adjective Greatest in quantity or highest in degree attainable or attained

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The highest limit.
• noun mathematics The greatest value of a set or other mathematical structure, especially the global maximum or a local maximum of a function.
• noun analysis An upper bound of a set which is also an element of that set.
• noun statistics The largest value of a batch or sample or the upper bound of a probability distribution.
• noun colloquial, snooker A 147 break; the highest possible break.
• noun colloquial, darts A score of 180 with three darts.
• noun colloquial, cricket A scoring shot for 6 runs.
• adjective To the highest degree.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective the greatest or most complete or best possible
• noun the greatest possible degree
• noun the largest possible quantity
• noun the point on a curve where the tangent changes from positive on the left to negative on the right