1. to tune (a musical instrument) again or differently
2. to adjust the frequency of a radio or television to a different station or channel
3. to modify or adjust something to make it work better or differently

Examples

• The guitarist had to retune his instrument after the string broke.
• She retuned the radio to find a clearer signal.
• The mechanic will retune the engine for better performance.
• After moving to a new city, we had to retune our television.
• The piano needs to be retuned after being moved.
• He retuned his approach to the problem after the first attempt failed.