1.
preventive measure; precaution; preventative measure
An action or plan taken in advance to prevent something undesirable from happening, such as disease, accidents, or problems.
Common collocations: 予防策を講じる (to take/implement preventive measures), 予防策を立てる (to establish preventive measures). The suffix ～策 (measure, plan) appears in many compound nouns: 対策 (countermeasure), 解決策 (solution), 改善策 (improvement measure). Related: 予防 (prevention), 対策 (countermeasure — reactive rather than preventive).