La palabra del día: Demanda

From Latin, formed by the prefix de, direction from above to below, manus, hand, and dare, to give. It can be translated into English as request, request form, application.
Demanda is a feminine noun (la/una) and in Legal Spanish refers to the written document with which a process normally begins and in which, exposing the facts and the legal bases that are created applicable, the judge is asked for a ruling favourable to a certain claim (entry 9).
Regarding the verb, we usually say demandar but it is also accepted inciar una demanda, interponer una demanda or entablar una demanda. It is important not to go further because no other option is possible; hacer/pedir/requerir/solicitar una demanda are all of them incorrect.
The applicant is called el/la demandante or la (parte) demandante, and the defendant is called el/la demmandado/a or la (parte) demandada. If the last one decides to answer the claim, the verb is contestar a la demanda (not responder). And if the defendant decides to make a counterclaim, it is called contrademandar or interponer una contrademanda and the defendant will be called contrademandante.
In another note, la demanda, in economy, means demand, as opposite to la oferta: supply. dc