[1840–50; under- + things]This word is first recorded in the period 1840–50. Other words that entered Englishat around the same time include: bypass, flan, set piece, striation, warmupunder- is a prefixal use of under, as to indicate place or situation below or beneath (underbrush; undertow); lower in grade or dignity (undersheriff; understudy); of lesser degree, extent, or amount (undersized); or insufficiency (underfeed)