Note: Forms with initial am- instead of em-, which first appear in the noun in the sixteenth century and the verb in the seventeenth century, are of uncertain origin. Given the earlier use in nouns, their appearance may be a by-product of shift of stress to the initial syllable. The suggestion in the Oxford English Dictionary, third edition, that the change is due to association with ambage, does not seem very likely. — The meaning "forest, grove" attached to *būska-, whence the Picard masculine noun bus, busc, receded early before a Gallo-Romance derivative *buska, a re-formation of the Germanic etymon as a neuter collective plural noun, taken as feminine, whence Old French busche "piece of firewood," French bûche. This new formation, also with results in Occitan and Upper Italian dialects, represents a sense shift from "bush, thicket" to "wood collected for a fire" to "split piece of wood, splinter." For a detailed discussion of Romance and Germanic outcomes of būska- see Johannes Hubschmied, "Romanisch-germanische Wortprobleme I. Zur Geschichte von bois, bûche (mit Berücksichtigung der Ortsnamen)," Vox Romanica, Band 29 (1970), pp. 114-16. Within the framework of Germanic and Indo-European ablaut patterns as now understood, a lengthened grade *būska- is questionable, and one might have to appeal to variation of expressive vocabulary within Germanic. Hubschmid, however, works within J. Pokorny's framework, where an Indo-European root with a very general meaning and form, *beu-, *b^heu-, *b^heuə- "to swell," is subject to an indefinite number of ablaut variants and root extensions.

Note: For the initial am- in place of em- see note at ambush entry 1