Is kickshawses one of those weird words that Shakespeare coined? What does it mean?

Act I, Scene 3 of Shakespeare's Twelfth Night opens at Olivia's home. Sir Toby Belch — Olivia's uncle — and Sir Andrew Aguecheek have returned in the early hours after a night of drinking.

As their names suggest, Sir Toby Belch is earthy, crude, very fat, and jolly, and Sir Andrew Aguecheek, is tall, long, thin, and balding. (Ague is a chill or a fit of shivering.) What's more, Sir Andrew is rich and easy to fool, two characteristics that Sir Toby exploits to keep the spirits flowing.

In this scene, the witty Sir Toby appears to be flattering Sir Andrew. The audience recognizes that most of this flattery is actually veiled insult, but Sir Andrew is too drunk and too foolish to recognize it. Here, Sir Toby prods Sir Andrew into greater heights of boastfulness:

SIR ANDREW. I am a fellow o' th' strangest mind i'
th' world; I delight in masques and revels sometimes altogether.

SIR TOBY. Art thou good at these kickshawses, knight?

SIR ANDREW. As any man in Illyria, whatsoever he be, under the degree of my
betters; and yet I will not compare with an old man.

SIR TOBY. What is thy excellence in a galliard, knight?

SIR ANDREW. Faith, I can cut a caper.

Kickshaws (here used in the plural kickshawses) is a corruption of the French phrase quelque chose, meaning "something." Kickshaw has come to mean either a fancy dish or delicacy or anything considered intricate or worthless finery or frivolity. In Great Britain, kickshaws was often used derogatorily, indicating not just something frivolous, but specifically some pointless French finery or delicacy - inherently inferior to anything British. (Note also that a galliard is a type of popular, fast, French dance.)

Although Shakespeare's spelling of kickshaws is the one that caught on with later authors, he wasn't the only one to use the word, and likely not the first. English spellings had not yet been codified, so the sneering quelque chose that the English spoke took all sorts of spellings on paper, using different combinations of Cs, Ks, and Qs that were nearer or further from the French spelling or spelled more or less phonetically.