The Seahawks reached the agreement with Williams on Thursday as the team wrapped up its organized team activities. The Seahawks still have their mandatory three-day minicamp beginning Tuesday.
Williams will be entering his 12th season in the NFL, having spent his entire career until now with the Minnesota Vikings. Williams started 15 games last season for the Vikings with 3 1/2 sacks and an interception.
Seattle found success last season with a deep rotation along the defensive line, an area that took a hit during free agency following the Seahawks' Super Bowl title.
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