A single candle with a long wick and a small body — a sharp rejection of one direction that 'pins' price back.
The long tail (the 'nose') shows price pushed strongly one way then got rejected and closed back near the open. A bullish pin bar has a long lower wick; a bearish one a long upper wick.
It signals rejection at a level and a likely short-term reversal in the opposite direction of the wick, especially at support/resistance or a supply/demand zone.
One candle, small body at one end, a wick at least two-thirds of the total range on the other end, little wick on the body side. The direction of the tail points to where price was rejected.
Never trade a single candle in isolation. It only carries weight with context — location at a key level, the prevailing trend, and confirmation from the next candle or from volume. On its own it is a hint, not a signal.
Reading a definition is step one. Chart Bound drills you on spotting Pin Bar and dozens of other setups on live candles, and the Daily gives you one fresh chart to read every day. Free to start.