To putt is to hit a golf ball softly with a club, usually when you're close to the hole. Golfers use a special club called a putter when they're ready to putt.
The distance between your golf ball and the hole determines how you putt, but the stroke is generally gentle, intended to get the ball on the green or all the way into the hole. Unlike other golf strokes that send the ball arcing through the air, a putt is always meant to simply roll it. Putt is a Scottish word that originally meant "to shove" or "to push," and came to include the golf meaning in 1743.