contribute

Concise Oxford English Dictionary © 2008 Oxford University Press:
contribute /kənˈtrɪbjuːt, ˈkɒntrɪbjuːt/

▶verb give in order to help achieve or provide something.

■ (contribute to) help to cause or bring about.

– derivatives
contribution noun,
contributive /kənˈtrɪb-/ adjective,
contributor noun.

– origin C16 (earlier (ME) as contribution): from L. contribut-, contribuere ‘bring together, add’, from con- ‘with’ + tribuere ‘bestow’.

usage: The first pronunciation, which puts the stress on -tri-, is held to be the only correct one, despite the fact that the alternative, with the stress on con-, is older.