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to add; to add up; to sum up; to append; to annex
to increase; to gather (e.g. speed); to pick up
to include; to count in; to let join
to inflict (damage); to deal; to give
味が薄いので塩を少し加えてみてください。
Please add a little salt.
急に車がスピードを加えた。
The car suddenly picked up speed.
チームに新しい優秀なメンバーを加えた。
We added a new member.