Contrary to the common opinion, this name derives not from Latin bonifacius 'well-doer,' but from bonifatius, from bonum 'good' and fatum 'fate.' The change to Bonifacius was due to pronunciation and from this was deduced a false etymology. Bonifatius is frequent on Latin inscriptions. Bonifacius is found only twice and these late (Thesaurus) ["Dictionary of English Surnames"]To be able to say Bo! to a goose is to be not quite destitute of courage, to have an inkling of spirit, and was probably in the first instance used of children. A little boy who comes across some geese suddenly will find himself hissed at immediately, and a great demonstration of defiance made by them, but if he can pluck up heart to cry 'bo!' loudly and advance upon them, they will retire defeated. The word 'bo' is clearly selected for the sake of the explosiveness of its first letter and the openness and loudness of its vowel. [Walter W. Skeat, "Cry Bo to a Goose, "Notes and Queries," 4th series vi Sept. 10, 1870]
At the end of every session the dominie had the satirical custom of presenting his tawse as a "booby-prize" to some idle or stupid lout whom he picked out as meriting this distinction so that next time they met he might start fresh and fair with new pair for a new set of classes. [Ascott R. Hope, "Dumps," "Young England" magazine, 1883]