弱力 (Jio̍k-la̍t) (weak interaction) 是 (sī)自然界 (chū-jiân-kài)4種 (chióng)基本力 (ki-pún-la̍t)的 (ê)1種,嘛 (mā)號 (hō)做 (chò)弱核子力 (jio̍k-hu̍t-chú-la̍t) (weak nuclear force)。佇 (Tī)粒子 (lia̍p-chú)物理學 (bu̍t-lí-ha̍k)的標準 (phiau-chún)模型 (bô͘-hêng) (Standard Model),弱力是靠 (khò)交換 (kau-oāⁿ)W甘 (ham)Z boson來 (lâi)發生 (hoat-seng)作用 (chok-iōng)。弱力會 (ē)造成 (chō-chiâⁿ)原子核 (goân-chú-hu̍t)中子 (tiong-chú)的β衰變 (soe-piàn) (beta decay),衰變閣 (koh)會有 (ū)輻射線 (hok-siā-soàⁿ) (radioactivity)。弱力是第 (tē)3強 (kiông)的基本力,並 (phēng)重力 (tāng-la̍t)較 (khah)強,毋過 (m̄-koh)干焦 (kan-taⁿ)強力 (kiông-la̍t)的1/10¹³。