Definition from Wiktionary, the free dictionary
- (Internet) Initialism of X-No-Archive.
XNA (plural XNAs)
- (biochemistry) nucleic acid analogue (nucleic acid analog) ; Initialism of xeno nucleic acid. (backformation) ; X nucleic acid, where "X" is a stand-in for multitude of various nucleic acid acronyms, which are not DNA or RNA