<ns3:p><ns3:bold>Background: </ns3:bold>Communicating about antimicrobial resistance (AMR) to the public is challenging. </ns3:p><ns3:p> <ns3:bold>Methods: </ns3:bold>We developed a dictionary of terms commonly used to communicate about AMR. For each term, we developed learning points to explain AMR and related concepts in plain language. We conducted a pilot evaluation in 374 high school students in Ubon Ratchathani, Thailand. In three 50-minute sessions, students were asked to answer five true/false questions using a paper-based questionnaire. The first session assessed their understanding of AMR at baseline, the second after searching the internet, and the third after the provision of the printed AMR dictionary and its web address. </ns3:p><ns3:p> <ns3:bold>Results: </ns3:bold>We developed the AMR dictionary as a web-based application (<ns3:ext-link xmlns:ns4="http://www.w3.org/1999/xlink" ext-link-type="uri" ns4:href="https://www.amrdictionary.net/">www.amrdictionary.net</ns3:ext-link>). The Thai version of the AMR dictionary included 35 terms and associated learning points, seven figures displaying posters promoting AMR awareness in Thailand, and 66 recommended online videos. In the pretest, the proportion of correct responses to each question ranged from 10% to 57%; 10% of the students correctly answered that antibiotics cannot kill viruses and 57% correctly answered that unnecessary use of antibiotics makes them ineffective. After the internet searches, the proportions of correct answers increased, ranging from 62% to 89% (all p<0.001). After providing the AMR dictionary, the proportions of correct answers increased further, ranging from 79% to 89% for three questions (p<0.001), and did not change for one question (p=0.15). Correct responses as to whether taking antibiotics often has side-effects such as diarrhoea reduced from 85% to 74% (p<0.001). The dictionary was revised based on the findings and comments received.</ns3:p><ns3:p> <ns3:bold>Conclusions: </ns3:bold>Understanding of AMR among Thai high school students is limited. The AMR dictionary can be a useful supportive tool to increase awareness and improve understanding of AMR. Our findings support the need to evaluate the effectiveness of communication tools in the real-world setting.</ns3:p>
