What is the name of the nonharmonic tone that occurs at the same time as the chord and resolves to a chord tone?

The nonharmonic tone that occurs at the same time as the chord and resolves to a chord tone is known as a suspension. This term describes a note that is sustained from a previous harmony, creating a momentary dissonance with the current chord before it resolves downward to a chord tone.

Suspensions are typically approached by the same pitch from which they were sustained and then resolved down a step to the next tone in the chord, thereby creating a tension and release effect that adds emotional depth to the music. This characteristic of suspensions is essential for building harmonic interest and creating a sense of movement within a piece.

In contrast, other nonharmonic tones such as neighbor tones, appoggiaturas, and passing tones have different functions and resolutions. Neighbor tones move away from the chord tone and return to it, appoggiaturas leap to a nonharmonic note and usually resolve by step to a chord tone, and passing tones connect two chord tones by stepping between them. These distinctions highlight why the suspension specifically fits the description provided in the question.