Today’s morning name. So obviously Latin, a 2nd-declension neuter noun. But apparently not; instead it’s a mystery. OED2 on tantrum: Etymology: Origin unascertained. colloquial. An outburst or display of petulance or ill-temper; a fit of passion. Frequently in plural. Now often spec. a fit of bad temper in a young child. [1st cite: 1714 E. Verney Let. 30 Oct. in M. … Continue reading tantrum