Also nurseshot, nursery shot, nursery cannon.
In carom games such as straight rail, balkline and cushion caroms, where all the balls are kept near each other and a cushion, and with very soft shots, can be "nursed" down a rail on multiple successful shots that effectively replicate the same ball setup so that the nurseshot can be repeated again (and again, etc.).
Excessive use of nurse shots by players skilled enough to set them up and pull them off repeatedly at will is what led to the development of the balklinecarombilliardsgame variations, and repetitive shot limitation rules in Englishbilliards. A clear example of why: In 1907, Tom Reece scored a record break of 499,135 consecutive points over a period of five weeks, without a miss, using the cradle cannonnurseshot.