[1795–1805; bi-1 + -cephalous]This word is first recorded in the period 1795–1805. Other words that entered Englishat around the same time include: hopscotch, kingpin, mirage, sensitivity, steeplechasebi- is a combining form meaning “twice,” “two,” used in the formation of compound words.Other words that use the affix bi- include: bilabial, bilingual, bimodal, bipolar, bivalve