doolally tap

Etymology
From (the name of a former British army camp 100 miles north-east of Bombay, used as a transit station for soldiers awaiting transport back to Britain) +  (from 🇨🇬 or 🇨🇬, ultimately from ).

According to one theory, to go doolally tap was to go crazy waiting.

Noun

 * 1) Camp fever; by extension, madness, eccentricity.

Adjective

 * 1)  Mad, insane, eccentric.