concessional

con ces sion al |kənˈseSHənl kənˌsɛʃən (ə )l | ▶adjective [ attrib. ] (of a rate or allowance ) constituting a concession: concessional and commercial types of loans.

concessional

con |ces ¦sion ¦al ▶adjective (of a rate or allowance ) constituting a concession: a concessional interest rate.