It's . . .

Supercalifragilisticexpialidocious!
Even though the sound of it
is something quite atrocious
If you say it loud enough you'll
always sound precocious
Supercalifragilisticexpialidocious!
Um diddle diddle diddle
um diddle ay! (etc.)

Because I was afraid to speak
when I was just a lad
Me father gave me nose
a tweak
and told me I was bad
But them one day I learned
a word
That saved me achin' nose
The biggest word I ever heard
And this is how it goes: Oh!

Supercalifragilisticexpialidocious!
Even though the sound of it
is something quite atrocious
If you say it loud enough you'll
always sound precocious
Supercalifragilisticexpialidocious!
Um diddle diddle diddle
um diddle ay! (etc.)

He traveled all around
the world
And everywhere he went
He'd use his word and all
would say
"There goes a clever gent"
When dukes and maharajas
pass the time of day with me
I say me special word and then
they ask me out to tea

Supercalifragilisticexpialidocious!
Even though the sound of it
is something quite atrocious
If you say it loud enough you'll
always sound precocious
Supercalifragilisticexpialidocious!
Um diddle diddle diddle
um diddle ay! (etc.)

So when the cat had got
your tongue
There's no need for dismay
Just summon up this word
and then
You've got a lot to say
But better say it carefully or it
could change your life . . .
She's
Supercalifragilisticexpialidocious!
Supercalifragilisticexpialidocious!
Supercalifragilisticexpialidocious!
Supercalifragilisticexpialidocious!