Definitions for "Safety play"
A play whereby the declarer maximizes the chances for fulfilling the contract (or achieving a certain score) by avoiding a play which might achieve slightly higher score, but at a greater risk if the arrangement of the cards is unfavorable.
a play maximizing the chances for a certain score by, possibly neglecting a slightly higher score
A strategy to leave your opponent with the minimum good moves possible.
the surest line to make the contract, disregarding extra tricks that might be made in some other way.