Beautiful day or valley
Daylynn is a modern American invention, likely created by combining the English word 'day' with the popular suffix 'lynn'. It may also be interpreted as a variant of Dallin, an Old English name meaning 'from the valley'.
Less common today
Daylynn isn't in the latest US Top 1000. It last peaked at #5,963 in 2015.
US births per 5-year period, 1990βpresent (SSA data).