I’ve seen this really often, mainly at the end of British names… for example, Sir Randy Jogalot (Bart.), or Lord Wibby Doodah (Esq.). What do they mean??
I know "Esq
“Bart.” is the abbreviation for “Baronet,” a heriditary title indictaed by “Sir” in front of the holder’s name. The reason for the abbreviation is that knighthoods also use “Sir” but are not herediatary, so your baronet wants to make sure that there’s no confusion between him, with his “been in the family for years” baronetcy, and those flash-in-the-pan common knights.
Oops. This is why I wish we could edit our posts. 
I was going to say, I know ‘Esq.’ means ‘Esquire’, which is an honorable title in the British gentry. I looked it up and found out it’s the rank directly below a knight. I also looked up ‘Bart.’ and found it was also a rank of gentry, meaning ‘Baronet’…this one is below barons and above knights.
Or, in my humble opinion, just an attempt to look somewhat sophisticated in today’s society which, for the most part, probably has little use for such titles. I don’t believe Bill Gates has an addition to his name, heh…
Check out the Staff Report on How do I get to be an Esquire? I’ll just add that in the UK, Esq can also indicate a person who has taken their undergraduate degree. But like the Report says, nobody is supposed to refer to themselves as Esquire.
esquire means you’re a lawyer
Only in the United States. In Britain it can have a broader meaning, and lawyers in other countries, like Canada, don’t use it.
Bart. is indeed an abbreviation of Baronet, a hereditary knighthood, although the abbreviation Bt. is more commonly used.
Esquire is more complicated. Normal usage is that it is simply an alternative to Mr - I know of no one who attempt to use it correctly, it is simply used as a formal alternative to all and sundry.
Technically however, it should be restricted to the following people -
- The sons of peers, baronets and knights.
- The eldest sons of the sons of peers and in turn their eldest sons in perpertuity.
- The eldest son of the eldest son of a knight or baronet, and their eldest sons in perpertuity.
- Companions of orders of knighthood (i.e. CBE, CVO, CMG, CB)
- Military Officers above the rank of Captain
- JPs (Justices of the Peace)
- County Sherrifs
- QCs (senior barristers)
- Deputy Lieutenants
- King of Arms and Heralds of Arms
- Serjeants at Arms, Serjeants at Law
- Principal Officers of HM Household
- Anyone referred to as an Esquire in Royal Warrants, Patents or Commissons
- Anyone who ranks above an Esquire in the order of precedence (hence all peers, Privy Councillors, Judges, Bishops and all members of the Order of the British Empire)
As I said, while this is formally correct, no-one pays any attention to it. The Royal College of Arms, for example, which if anywhere is going to be a stickler for protocol should be, addresses all men as Esq. Oh, and in case anyone asks - I haven’t faintest idea what a Serjeant-at-Law is 
They were a type of senior barrister who had the right to appear in the court of common pleas. They were abolished in the late nineteenth century.
The question as to who in England was an esquire has always been a matter of great uncertainty. Ever since the term was introduced in the later middle ages, there have been disagreements over its use - was it defined by land or by office, was it hereditary? - and the attempted definitions have themselves shifted over time.
This is one example of how definitions have shifted. There was a time when many people (OK, those who considered themselves to be esquires) would have been appalled at the idea that mere graduates were esquires. The only degrees which conferred that rank were doctorates (although some would have queried that), with lesser graduates being only ‘gentlemen’ and they were jolly lucky to count even as that. Graduates only became ‘esquires’ once the term began to be applied to all ‘gentlemen’.
Social usage of this type usually broadens out over time, mainly because, if in doubt, it is better to flatter someone than to offend them. Only those terms which are very precisely defined, such as peerage titles or baronetcies, remain fixed. It has now got to the point where using ‘esquire’ in any context at all can be thought archaic.