The earliest meaning of pollution (early 1300s) was the discharge of semen without sexual intercourse. Masturbate (the earlier English word was mastuprate) is from the Latin manus stuprare (defile with the hand). The modern meaning of pollution, contamination of the environment, dates from the 1870s but was not common until the 1950s. Pollute is from the Latin polluere (to soil or defile, from por, before, and lutum, mud). The earliest meaning of contaminate was to make impure by contact. Other words from the root tangere (to touch) are contagion (a disease communicated by touch); intact (untouched); tact (a sense of touch); and taste (the earliest meaning was to examine or explore by touch).