[1945–50; goit(e)r + -o- + -gen]This word is first recorded in the period 1945–50. Other words that entered Englishat around the same time include: individual medley, on-line, spin-off, synchronized swimming, taxi squad-o- is the typical ending of the first element of compounds of Greek origin (as -i- is, in compounds of Latin origin), used regularly in forming new compounds with elementsof Greek origin and often used in English as a connective irrespective of etymology(Franco-Italian; geography; seriocomic; speedometer); -gen is a combining form meaning “that which produces,” used in the formation of compoundwords. Other words that use the affix -gen include: endogen, hydrogen