adjective - performing or functioning in the best possible manner with the least waste of time and effort

noun - (the chemical element of atomic number 19) a silvery-white metal of the alkali-metal group

noun - the counter in a supermarket at which you pay for the goods you want to buy

noun, formal - the act of opening the body of a dead person to find out why they died

noun - the act of opening the body of a dead person to find out why they died

noun - the state of there being too many people in the world or in one particular area

verb - to make a sound more quiet, especially by wrapping the source of the sound in something

noun - the bushes, tall grass, ferns, etc. that grow under the trees in a wood or forest

verb - a modal verb that expresses the idea that something was common, usual, regular in the past

noun, informal - the dried up substance that sometimes appears in the corner of your eye when you sleep

noun, informal - the dried up substance that sometimes appears in the corner of your eyes when you sleep

noun - the act of injecting someone with a special substance that will stimulate the production of antibodies

noun - the act of injecting someone with a special substance that will stimulate the production of antibodies

noun - the process of checking that everything (all the equipment etc.) is ready for a concert etc.

noun - the period of time when a patient's illness becomes less severe and the symptoms go away