earmark
n.
mid-15c., from ear, n.1 + mark, n.1. Originally a cut or mark in the ear of sheep and cattle, serving as a sign of ownership (also a punishment of certain criminals); first recorded 1570s in figurative sense "stamp of ownership."
v.
1590s, "to identify by an earmark," from earmark, n.. Meaning "to set aside money for a special purpose" is attested by 1868. Related: Earmarked; earmarking.