[¦liŋ·kər dē‚äk·sē‚rī·bō·nü¦klē·lk ′as·əd] (cell and molecular biology) A short, synthetic deoxyribonucleic acid (DNA) molecule that contains the recognition site for a specific restriction endonuclease. Also known as linker.A segment of DNA to which lysine-rich histone is bound and which connects the adjacent nucleosomes of a chromosome.