Senior Counsel

What does this mean again? We don’t want you to leave..but you’re not going any further up the chain kind of thing? 

Depends on context.

US firms use 'senior of counsel' the way UK firms use 'consultant' for wise old dudes who don't want to retire.

Inhouse it's a sort of senior associate type of thing usually.

You have a great user name (assuming you are referencing Mad Men). I recognise this is of no assistance vis-a-vis your query.

Those whose answers reference the bar / QCs - you're presumably not great at reading context.

Wot Dal said about Ireland, etc.

In a US firm where I worked it was used either as a sop to lawyers who were getting really senior but were never going to make partner, or for very senior partners who were sort of semi-retired.  I'd assume they were not contributing enough to stay in the partnership but they were not quite ready to hang up their practising certificates so the firm gave them a kind of elder statesman title.