1 the act of applying, esp. medicinal ointment to the skin.
2 a formal request, usu. in writing, for employment, membership, etc.
3 a relevance. b the use to which something can or should be put.
4 sustained or concentrated effort; diligence.
Etymology: ME f. F f. L applicatio -onis (as APPLY, -ATION)
Useful english dictionary. 2012.