A recent study by Bruine de Bruin, Clim Change 167, 2021 investigated how well laypeople understand eight key termini of climate change that are commonly used in IPCC reports (i.e. mitigation, carbon neutral, unprecedented transition, tipping point, sustainable development, carbon dioxide removal, adaptation, abrupt change). The results revealed systematic misinterpretations by participants. To improve laypeople’s understanding of these termini, Bruine de Bruin et al. developed recommendations for alternative formulations but did not test whether these alternative formulations actually increase understanding and lead to changes of people’s intentions to behave sustainably. To fill this gap, we carried out a preregistered online experiment (N = 285) and compared the altered with the original formulations in terms of how well participants understand the termini subjectively and objectively. In addition, we measured participants’ confidence in the correctness of their understanding and their intention to act sustainably. The results indicate that participants in the altered wording group (1) generally understood the termini better subjectively and objectively; (2) had more confidence in the correctness of their understanding, and (3) misinterpreted the termini less by relying on their mental models of non-climate contexts (where the termini often have different meanings). Interestingly, this overall pattern did not apply to all termini, indicating that altering the termini increased people’s understanding for some concepts but not for others. Moreover, the altered wordings did not increase participants’ intentions to act sustainably. Implications and further directions are discussed.