Green’s Dictionary of Slang

1. (UK Und.) to smarten oneself up.

1865		Leaves from Diary of Celebrated Burglar 25/1: Fobs had been ‘starching’ himself up for her, and fancied himself ‘rye-buck’ on that ‘figure’.
1915		H.E. Rollins ‘A West Texas Word List’ in DN IV:iii 229: starch, v. To powder one’s face. ‘Let me starch my face before we go.’.

2. to kill, to die.

1957		(con. 1943) A. Myrer Big War 213: Two guys got starched on Pari ’cause they were going around on some fool errand. [Ibid.] 364: I hope he starches you good and proper.
1960		(con. 1940s) D. MacCuish Do Not Go Gentle (1962) 195: I was so friggin’ mad I almost starched him.
1983		N. Proffitt Gardens of Stone (1985) 11: Don’t be in such a hurry to get starched, kid.