Boskō (βόσκω) means to feed or graze animals — to tend to their nourishment by leading them to pasture. The word is used for shepherds feeding their flocks and herdsmen tending pigs. Its most theologically significant use is in the post-resurrection dialogue between Jesus and Peter in John 21, where Jesus commands Peter to "feed" His sheep.
The threefold command to "feed" (boskō) and "tend" (poimainō) in John 21:15-17 is both Peter's restoration and his commission. Jesus, the Good Shepherd who laid down His life for the sheep (John 10:11), delegates the pastoral feeding of His flock to human shepherds. Every pastor and elder fulfills this charge. Faithful ministry is fundamentally an act of feeding — nourishing God's people on the Word of life.