The sixth generation (6G) of mobile communications and beyond is expected to enable advanced functionalities, such as integrated sensing and communication (ISAC), while involving diverse terminal/user equipment types from terrestrial to non-terrestrial networks. As waveforms are acknowledged as a fundamental technology driving 6G and beyond, this article presents a contribution in this technical domain. First, it provides an overview of several standardized communication waveforms, as well as chirp-based waveforms for radar sensing and Internet of Things (IoT) applications. This article then presents single-carrier chirping waveform: discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) with chirping. Its fundamental principles, key properties, performances, and advantages are examined from both communication and sensing perspectives. Finally, several future research directions are outlined to further explore its potential and opportunities for ISAC.