3 letters:
lun

4 letters:
lani, leny, lini, loni, luhn, lund, lunn, lunt, lunz

5 letters:
bunny, funny, gunny, honey, laney, lanni, lanny, lenny, loney, lonny, loony, lovie, lucky, luddy, lulie, lunch, lunde, lundt, lundy, lunge, luthy, money, runny, sonny, sunny, tunny, lunny

6 letters:
bunney, bunnie, lennie, leonie, linney, lonnie, looney, lowney, luckey, luckie, tunney

8 letters:
loughney