"proud, arrogant," 1918, noted that year as college slang, from snoot (n.) + -y (2). Probably with suggestions of snouty (1858); the notion being of "looking down one's nose." Related: Snootily; snootiness.
snookums
snoop
snoopy
snoot
snootful
snooty
snooze
snore
snorkel
snort
snot