\On"set`\
On + set.
1. A rushing or setting upon; an attack; an assault; a storming; especially, the assault of an army. --Milton .
The onset and retire Of both your armies. --Shak.
Who on that day the word of onset gave.
--Wordsworth
2. A setting about; a beginning (Obs.) --Shak.
There is surely no greater wisdom than well to time
the beginnings and onsets of things. --Bacon .
3. Anything set on, or added, as an ornament or as a useful appendage. (Obs.) ----Johnson .
1. To assault; to set upon. (Obs.)
2. To set about; to begin. (Obs.) --Carew .