tithe

Concise Oxford English Dictionary © 2008 Oxford University Press:
tithe /tʌɪð/

▶noun

• 1 one tenth of annual produce or earnings, formerly taken as a tax for the support of the Church and clergy.

• 2 archaic a tenth of a specified thing.

▶verb subject to or pay as a tithe.

– derivatives
tithable adjective.

– origin OE tēotha (adj. in the ordinal sense ‘tenth’, used in a specialized sense as a noun), tēothian (v.).