The name is of Frisian origin and could either be a diminutive form of Dietrich or come directly from the Frisian word til meaning, “good; hard.”
The name was borne by a medieval German folk hero, Till Eulenspiegel, a famous 13th-century prankster who appears in several medieval pamphlets.
It is currently borne by Rammstein singer, Till Lindemann, (b.1960).
Currently, Till is the 48th most popular male name in Germany, (2011).
Another form is Dil/Dyl.