Possible Clues:

• It's given as a greeting
• Fish with a soft back
• Turn soft and fish like this
• Touch lightly, as water
• Fistbump
• Drop bait lightly on the water
• That will make Father sound soft and fishy
• High five cousin
• Fish by dropping bait lightly
• "The Sacred Art of Giving __": Ta-Nehisi Coates essay about a friendly greeting