Attire vs Getup - What's the difference?

As a verb attire

is .

(chiefly|us|informal) a costume or outfit, especially one that is ostentatious or otherwise unusual.

(en noun)

One's dress; what one wears; one's clothes.

He was wearing his formal attire .

(heraldiccharge) The single horn of a deer or stag.

To dress or garb.

We will attire him in fine clothing so he can make a good impression.

He stood there, attired in his best clothes, waiting for applause.

* ----

* get up * get-up

(en noun)

(chiefly, US, informal) A costume or outfit, especially one that is ostentatious or otherwise unusual.

*1899 ,

When near the buildings I met a white man, in such an unexpected elegance of get–up that in the first moment I took him for a sort of vision.

* 1917 , " 1,200 Reading Firemen March," Reading Eagle (Pennsylvania, USA), 28 Oct. p. 4:

The Schnitzelbank Band, each member attired in an odd getup , received many comments for the manner in which the men marched.

* 2009 , " Worried They Will Miss the War: Inside the Mind of West Point's Class of 2009," Newsweek , 6 June:

[A] parade of costumed cadets trots by: a shark costume, an Uncle Sam getup and three young men in form-fitting bodysuits.

(informal) A fight or altercation.

* 2002 , Andrea Sachs, " Caricature Builder," Time , 21 Jan.:

"A bully. Picked on fellows. He loved to fight. But I never saw him in a getup with a fellow his own size."

(publishing) Layout and production style, as of a magazine.