“thy fault is youth, some wantonness”
'Wantonness' meant reckless, undisciplined behavior — pleasure-seeking without self-restraint, and often specifically sexual license. The word set the charge the speaker is weighing: some critics call the youth's conduct mere youthful excess, others call it deliberate lewdness.
“lov'd of more and less”
'More and less' is an Elizabethan idiom meaning 'great and small' — that is, people of high rank and people of low rank alike. The line says the youth is loved by everyone across the entire social order, not just by one class of admirer.
- TLN 1339biblical allusion
“lambs might the stern wolf betray, / If like a lamb he could his looks translate”
The image of a wolf disguised as a lamb comes from Jesus's warning in Matthew 7:15: 'Beware of false prophets, which come to you in sheepes clothing, but inwardly they are rauening wolues' (Geneva 1599). The speaker turns the image on the youth: because he already looks innocent, he could, if he chose, deceive any number of unsuspecting admirers as effectively as a wolf in a fleece.
“the strength of all thy state”
'State' here means the full weight of the youth's social standing, personal authority, and physical magnetism combined — the total power his rank and presence give him over those who see him. 'The strength of all thy state' is the maximum force he could bring to bear if he chose to use it deliberately.