the arithmetic operation of summing; calculating the sum of two or more numbers; "the summation of four and three gives seven"; "four plus three equals seven"
a concluding summary (as in presenting a case before a law court)
(physiology) the process whereby multiple stimuli can produce a response (in a muscle or nerve or other part) that one stimulus alone does not produce
absolutely required and not to be used up or sacrificed
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
being or relating to or containing the essence of a plant etc; "essential oil"
(chemistry) a surface forming a common boundary between two things (two objects or liquids or chemical phases)
(computer science) computer circuit consisting of the hardware and associated circuitry that links one device with another (especially a computer and a hard disk drive or other peripherals)
the overlap where two theories or phenomena affect each other or have links with each other; "the interface between chemistry and biology"
(computer science) a program that controls a display for the user (usually on a computer monitor) and that allows the user to interact with the system
the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"
a single whole grain of a cereal; "a kernel of corn"
the inner and usually edible part of a seed or grain or nut or fruit stone; "black walnut kernels are difficult to get out of the shell"
a variable quantity that can be resolved into components
any agent (person or animal or microorganism) that carries and transmits a disease; "mosquitos are vectors of malaria and yellow fever"; "fleas are vectors of the plague"; "aphids are transmitters of plant diseases"; "when medical scientists talk about vectors they are usually talking about insects"
a straight line segment whose length is magnitude and whose orientation in space is direction