This about sums up my morning:
The Lady in my Life was affronted and offended I didn’t recognise a spurtle, when one was waved in my face.
Oddly enough, nor does the spell-check here, which keeps “correcting” to spurt.
The OED shyly admits being at a bit of an etymological loss. It speculates a connection from spartle, which connects to spatula, which is an anglicising of spatule, which is a vamp on spatula. Which all looks like very hard work.
Whereas a spirtle is a little spurt.
And a thieval? Which the spell-check renders serially and unhelpfully as thieves. Ah, yes: here we enter another OED morass:
In form, thῑvel seems to correspond to Old English þyfel ‘bush, leafy plant’, but no links of connection between this and the modern sense have been found. In its various current forms the word is in use from N. of Scotl. to S. Lancashire, W. and E. Yorkshire; this localization suggests a Norse origin, and it has been referred to Old Icelandic þefja /ˈθɛvja/ ; but this is a very rare word of doubtful standing, and in any case meant ‘to thicken by beating or stamping’ rather than ‘to stir’. The actual Old Norse name for a stirring-stick was þvara, between which and thivel there is of course no connection.