de·mand 
(dĭ-mănd)
(dĭ-mănd)v. de·mand·ed, de·mand·ing, de·mands
v.tr.
1. To ask for urgently or peremptorily: demand an investigation into the murder; demanding that he leave immediately; demanded to speak to the manager.
2. To claim as just or due: demand repayment of a loan.
3. To ask to be informed of: demanded an explanation for the interruption.
4. To require as useful, just, proper, or necessary; call for: a gem that demands a fine setting.
5. Law
a. To lay legal claim to; claim formally.
b. To ask that (something) be done in accordance with a legal requirement.
v.intr.
To make a demand.
n.
Idiom: 1. An act of demanding; an urgent request.
2. Something demanded: on strike until they get their demands.
3. An urgent requirement or need: the heavy demands of her job; the emotional demands of his marriage; an increased oxygen demand.
4. The state of being sought after: in great demand as a speaker.
5. Economics The desire for goods or services in an economy, measured as the amount people are ready to buy at a given price: Supply should rise to meet demand.
6. Law
a. A formal claim.
b. A request that some act be done or payment made in accordance with a legal requirement.
7. Archaic An emphatic question or inquiry.
on demand
1. When presented for payment: a note payable on demand.
2. When needed or asked for: fed the baby on demand.
[Middle English demanden, from Old French demander, to charge with doing, and from Medieval Latin dēmandāre, to demand, both from Latin, to entrust : dē-, de- + mandāre, to entrust; see man-2 in the Appendix of Indo-European roots.]
de·manda·ble adj.
de·mander n.