Donald Trump was much mocked last week when he said that he was going to ‘win bigly’. In fact, Donald Trump does quite a lot of things bigly. The adverb bigly is in the Oxford English Dictionary – described as ‘now rare’, unsurprisingly – and is defined as “loudly, boastfully; proudly, haughtily, pompously”. That definition dates back to the late 15th century. One of the citations is from Thomas Hardy’s Far from the Madding Crowd:
'I don't see that I deserve to be put upon and stormed at for nothing!’ concluded the small woman, bigly.'
There is an earlier meaning – “with great force; firmly, violently; stoutly, strongly”. That meaning was in use in the late 14th century.
There is also an entry in the OED for bigly as an adjective (not how Trump used it - he clearly meant to use an adverb), which is completely unrelated to the adjective big. It comes from an old Scandinavian word meaning ‘to live in, dwell’, and is defined as “habitable, fit to live in; and hence, pleasant”. It is a relative of the Old English verb būan, to live. The Dictionary says that the word is now restricted to Scotland, the north of England, and Ireland.