1630s, verbal noun from present participle of block (v.2). By 1891 in U.S. football; by 1961 in theater.
Entries linking to blocking
block v.2
"make smooth or to give shape on a block," 1620s, from block (n.1). The meaning "form into a block" is by 1863; that of "strengthen or support by blocks" is from 1881. The theater sense "designate the position on stage of each actor in a scene" is by 1961. Related: Blocked; blocking.