means The phenomenon where a system vibrates with greater amplitude when pushed at its natural frequency — and, more loosely, the quality of striking a deep chord, emotional or otherwise.

from From Latin resonare, 'to sound again, to echo,' built from re- ('back, again') and sonare ('to sound') — the same sonare that gives us 'sonic' and 'sonnet.' It entered English by way of French resonance, first as a word for literal ringing and echoing sound, only later widening to describe anything that vibrates in sympathy, from a tuning fork to a heart.