- cause to change

- make different

- cause a transformation
"The advent of the automobile may have altered the growth pattern of the city"
"The discussion has changed my thinking about the issue"

- make less severe or harsh or extreme
"please modify this letter to make it more polite"
"he modified his views on same-gender marriage"

- add a modifier to a constituent

1. To change somewhat the form or qualities of; to alter somewhat; as, to modify a contrivance adapted to some mechanical purpose; to modify the terms of a contract.

2. To limit or reduce in extent or degree; to moderate; to qualify; to lower.

"Of his grace He modifies his first severe decree." -- Dryden.