infomercial UK /ˈɪnfəˌmɜːʃəl/US /ˈɪnfəˌmɝʃəl/ noun1 •A program-length television commercial, typically between thirty minutes and one hour long, that advertises a product or service by presenting supposedly impartial information about it.Dionne and I were both named after great singers of the past who now do infomercials. — 1995 formsinfomercials