blahs, the, n. — Green’s Dictionary of Slang

blahs, the n.

(Aus./US) depression, despondency, low condition.

1967–8		Baker et al. CUSS 81: Blahs, have the Have a minor illness, feel sick.
1970		Time 9 Nov. 36: Have trouble sleeping? Suffer from the pre-dawn blahs — wakefulness and worries at 4 a.m.?
1980		A. Pearl Dict. Popular Sl.
1998		Ebony LIII (Jan.) 104: [headline] How to Beat the Winter Blahs and Boost Your Energy.
2003		Family Fun 🌐 [heading] 25 Ways To Beat The Blahs – Activities to ward off winter boredom from FamilyFun.
2009		(con. 1960s) J. Ellroy Blood’s a Rover 24: Gas station ennui. It was hot and humid [...] The AC [...] perked him up [...] Gas station blahs, adieu.
2021		J. Ellroy Widespread Panic 108: I dexie-dosed my case of the blahs.