[1840–50; ‹ L aci- (comb. form of acus needle; cf. acicula) + -form]This word is first recorded in the period 1840–50. Other words that entered Englishat around the same time include: dope, flan, sensationalism, set piece, warmup-form is a combining form meaning “having the form of”. Other words that use the affix-form include: moniliform, somatoform, stratiform, tectiform, villiform