Definition of demand noun from the Oxford Advanced American Dictionary

Oxford3000

demand

noun
/dɪˈmænd/
 
 
1 [countable] demand (for something/that…) a very firm request for something; something that someone needsa demand for higher paydemands that the law on gun ownership should be changedfirms attempting to meet/satisfy their customers' demands (= to give them what they are asking for)2 demands [plural] demand (of something)demand (on someone) things that someone or something makes you do, especially things that are difficult, make you tired, worried, etc.the demands of children/workFlying makes enormous demands on pilots.She shouldn't always give in to his demands.3 [uncountable, countable] demand (for something/someone) the desire or need of customers for goods or services that they want to buy or useto meet the demand for a productThere's an increased demand for organic produce these days.Demand is exceeding supply.IDIOMS

by popular demand

because a lot of people have asked for something
By popular demand, the play will run for another week.by popular demand

in demand

wanted by a lot of people
Good nurses are always in demand.in demand

on demand

done or happening whenever someone asks
Feed the baby on demand.on-demand printing of bookson demand
see also supply and demand