Yes sir!yes siree! American informal slang
Used to describe the completely agreement of the opinion or incident.
Misa: Can you hang out with me to go shopping tomorrow? Lyn: Yes, siree!
Yes, siree, she was as beautiful as fairy in her wedding.
This expression is comparable to others as you'd better believe in God! But the origin is unclear. Some sources said that It appeared in the mid 19th century.
It seems that Siree is a lengthened form of Sir. Yes, sir, that is a polite affirmative response. Yes, a siree is a more casual way of saying the same thing. Bob may be a thin oath in which the word God is replaced by Bob. It may simply add yes, siree, to the implication of added excitement.
To say, or believe something or someone that seems completely crazy, delusional, or stupid
You spent 1000$ on a new pair of shoes! It is insanely crazy. You need your head examined.