Based on the above bit of Lucilius, I find myself rather doubting the dictionary definition of puellus. Perhaps it derives from a diminution of puer, but I think at very least its connotations are of a boy used as girl, i.e. for sexual purposes.
Cf. this rare deponent verb. All the rest of the words beginning puell- have strong feminine meaning as part of their denotations.
A quick word search shows just how rare this vocabulary is and its sexual overtones.
See C. Williams 2nd ed p. 301 n. 33
and the more extensive discussion by Chahoud.
Liv Mariah Yarrow 