base

1a architecture (1) :  the lower part of a wall, pier, or column considered as a separate architectural feature (2) :  the lower part of a complete architectural design (as of a monument)b :  the bottom of something considered as its support :  foundation the base of the mountain the lamp's heavy basec mathematics (1) :  a side or face (see ¹face 5a(5)) of a geometrical figure from which an altitude (see altitude 1c(1)) can be constructed; especially :  a side or face on which the figure stands the base of a triangle (2) :  the length of a base determining the triangle's based biology :  that part of a bodily organ by which it is attached to another more central structure of the organism the base of the thumb

2a :  a main ingredient paint having a latex baseb :  a supporting or carrying ingredient (as of a medicine)

3a :  the fundamental part of something :  groundwork, basis the book's theoretical base her broad base of knowledgeb :  something (as a group of people) that reliably provides support (such as for a business or political candidate) —usually singular efforts to expand their customer base the band's fan base But I do believe that that's a very sore point with many Democrats and could be used to energize their base. — John McCainc Marxism :  the economic factors on which all legal, social, and political relations are formed

4 heraldry :  the lower part of a heraldic field (see ¹field 3c)

5a :  the starting point or line for an action or undertaking plans to make this city his base of operation — J. A. Loftusb :  a baseline in surveyingc :  a center or area of operations The company has its base in London.: such as (1) :  the place from which a military force draws supplies (2) :  a place where military operations begin (3) :  a permanent military installation a naval base The troops were ordered back to base.d mathematics (1) :  a number (such as 5 in 5^6.44 or 5⁷) that is raised to a power (see ¹power 5a); especially :  the number that when raised to a power equal to the logarithm of a number yields the number itself The logarithm of 100 to the base 10 is 2 since 10² = 100. (2) :  a number equal to the number of units in a given digit's place (see ¹place 8) that for a given system of writing numbers is required to give the numeral 1 in the next higher place The decimal system uses a base of 10.; also :  such a system of writing numbers using an indicated base Convert from base 10 to base 2. (3) :  a number that is multiplied by a rate or of which a percentage or fraction is calculated To find the interest on $90 at 10 percent multiply the base 90 by .10.e linguistics :  root 6 “Leave” is the base of the verb “left.”

6a in various games :  the starting place or goalb :  any one of the four stations at the corners of a baseball or softball infield allowing the batter to reach basec :  a point to be considered His opening remarks touched every base.

7 chemistry a :  any of various typically water-soluble and bitter tasting compounds that in solution have a pH greater than 7, are capable of reacting with an acid to form a salt, and are molecules or ions able to take up a proton from an acid or able to give up an unshared pair of electrons to an acidb :  any of the five purine or pyrimidine bases of DNA and RNA that include cytosine, guanine, adenine, thymine, and uracil

8 finance :  a price level at which a security (see security 3) previously declining in price resists further decline