scrum (n.) 1888, abbreviation of scrummage, a variant form of scrimmage (n.). Transferred sense of "noisy throng" is from 1950.
scrumptious (adj.) 1833, in countrified humor writing of "Major Jack Downing" of Maine (Seba Smith); probably a colloquial alteration of sumptuous. Originally "stylish, splendid;" sense of "delicious" is by 1881. Related: Scrumptiously; scrumptiousness.