sprinkler (n.)

late 14c. (implied in sprinkled), frequentative of sprenge (see spring (v.)) or via Middle Dutch, Middle Low German sprenkel "spot, speck," from PIE root *(s)preg- "to jerk, scatter" (source also of Latin spargere "to scatter, sprinkle"). The meaning "rain lightly" is first recorded 1778.

1872, from lawn (n.1) + sprinkler.