means Not any thing; the absence of anything at all, or something of no importance or value.

from A squeezing-together of the Old English 'nan thing' — literally 'no thing.' That 'nan' is itself a compound of 'ne' (not) and 'an' (one), so the deepest bones of the word say 'not one thing.' English loves this trick: 'none,' 'no,' and 'never' all carry that same little 'ne-' of denial, an ancient particle of negation shared across the Germanic family and beyond. So 'nothing' is, etymologically, three layers of refusal stacked up — not + one + thing — to name the grand total of what's there.