Not having been coached (trained or instructed).(adjective)
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Use "uncoached" in a sentence
"The 50-year-old film all but crackles with age as the president makes his earnest, uncoached speech."
"Apparently, there is no good academic research on coached vs. uncoached runners, but experts everywhere say coaching works."
"A randomized trial of the effects of coached vs. uncoached maternal pushing during the second stage of labor on postpartum pelvic floor structure and function."