surge, fluctuation, undulation, pulsation

a sea, an ocean / a lake / (figuratively) an object covering over a large area, as in 血の海 (chi no umi, “pool of blood”) or 火の海 (hi no umi, “sea of fire”)

hard, tough, stiff / stubborn

against one's will

strong / strength / powerful / potent

(lengths of time) slightly more than

a male given name

strong, durable, powerful / strong, competent, good / high tolerance, resilient

strength

(quantum mechanics) wavefunction