1 noun return to worse statecúlú masc c m udul ar gcúl c m udue to a significant regression in the standard of livingmar gheall ar dhul ar gcúl suntasach sa chaighdeán maireachtála2 noun MED becoming less severelaghdú masc c m udul ar gcúl c m uthere's been a regression of the tumourtá an siad laghdaithe, tá an siad dulta ar gcúl3 noun PSYCH use of hypnosiscúlú masc c m u4 noun STAT statistical measurecúlchéimniú masc c m u