While decentering the human has been a key approach in posthumanist HCI, there are still questions and tensions around it. To address them, we outline emergent notions of decentering, tracing it back from HCI to critical posthumanism and connecting epistemological developments in the humanities to design scholarship. Then, reviewing how decentering is understood and practiced in HCI, we distill five emerging dimensions for articulating more-than-human practices. We conclude by unpacking “decentering through design” as an ongoing material practice through which more-than-human designers not only materialize (apply) posthuman theory but also “make” posthuman knowledge in their own unique ways.