(of verbs) having a suffix attached immediately to the stem, without an intervening vowel
athematic in American English
(ˌeiθiˈmætɪk)
adjective
inflected without a thematic vowel
Word origin
[1890–95; a-6 + thematic]This word is first recorded in the period 1890–95. Other words that entered Englishat around the same time include: blanket roll, blip, bootstrap, plein-air, takedown