Slang dictionary
shoulda
[shoo duh]
does shoulda mean?
Shoulda, woulda, coulda. Shoulda is simply a spelling of should have(ǰ should’ve), based on a common, contracted, colloquial pronunciation of this modal verb phrase.
Where does shoulda come from?

We might spell should have as such, but few of us actually pronounce it that way. The expression typically comes out sounding more likeshoulda, hence the spelling. Gonna (“going to”) and wanna (“want to”) are other such examples, with the unstressed to also rendered as an a.
Our bellybuttons shoulda jus been a button u press when u tryna die
— sosa stan acc (@folowmeontwiter)
Similarly, should have is also frequently (and questionably) rendered as should of.
People have certainly been sayingshoulda long before, but record of this colloquial spelling comes in the early 1900s. An early example appears in Collier’smagazine as the author’s way to reflect actual speech.
Examples of shoulda

Who uses shoulda?
Shoulda withthe samesenseasshould havebut is considered more informal or colloquial in writing.
Damn, I shoulda been a cowboy
— Wyatt McLellan🎩 (@McLellanWyatt)
It’s commonly used to express some obligation, command, or regret, a favorite way of lyricists to begin a line.
Can't wait for more "oh no I named my firstborn child Danaerys,"s tonight. Maybe ya shoulda waited for the series to finish ya dinguses
— youth in asia (@kidd0OW)
Toni Braxton, for instance, released “Love Shoulda Brought You Home” in 1992, followed shortly thereafter by Toby Keith’s hit song, “Should’ve Been a Cowboy,” popularly rendered with a shoulda.
Note
This is not meant to be a formal definition of shoulda like most terms we define on Dictionary.com, but is rather an informal word summary that hopefully touches upon the key aspects of the meaning and usage of shoulda that will help our users expand their word mastery.