Русско-англо-русский юридический словарь

The English requirement for consideration does not apply in Scotland, so it is possible to have a gratuitous contract, i.e. a contract where only one of the parties comes under any duties to the other (e.g. a contract to perform services for no consideration). If, however, consideration is given, as for example in a sales contract, the contract is said to be onerous. (Wikipedia)