強める
つよめる · tsuyomeru · JLPT N3 · verb-ichidan
to strengthen
💪 強める = 強い (tsuyoi, strong) + める (make) → make stronger
Swap the い of 強い for める and the adjective becomes a verb: to make something strong. The same pattern gives 弱める (yowameru, to weaken) and 高める (takameru, to raise), so learning one teaches the set.