lessen
v.v. to make something smaller, weaker, or less in amount. You use this when you want to reduce the strength of a feeling or the size of a problem.
v. to make or become less in amount, degree, or intensity. Often used to describe the reduction of abstract qualities like pain, impact, or risk.
Taking this medicine will help lessen the pain.
The new safety measures were designed to lessen the risk of accidents during the construction project.
While the initial shock of the news was profound, the passage of time served to lessen her grief, allowing her to focus on the future once more.
From Middle English lessenen, lasnen, equivalent to less + -en (verbal suffix).
Can be used both transitively (to lessen something) and intransitively (something lessens).