Background: Abnormal breathing, or “gasping,” frequently occurs during cardiac arrest and has been associated with increased survival. During 9-1-1 calls, early recognition of gasping may allow dispatchers to identify OHCA and to start CPR instructions promptly. Objective: To characterize lay rescuers’ descriptions of abnormal breathing during OHCA. Methods: 9-1-1 audio recordings of 4,279 confirmed OHCAs (10/10-7/14) in Arizona were reviewed by program personnel. Terms used by lay rescuers to describe victims’ breathing were recorded in a structured database. Results: Abnormal breathing (as opposed to “not breathing”) was described in 542/4279 (13%) calls. There were 623 verbal descriptions. A total of 50 different terms were used. However, the top 8 accounted for 83% and the remaining 42 descriptions (“Other”) comprised only 17% of all terms used. “Gasping” was the most commonly used term (30%; 187/623), followed by “snoring” (15%; 95/623; Figure). Conclusion: Lay rescuers used a wide variety of terms to describe abnormal breathing in documented OHCA. However, 8 terms accounted for 83% of descriptions. Familiarizing 9-1-1 telecommunicators with the most commonly used terms may improve the accuracy of recognition and hasten the identification of OHCA.