Soporifer

Part of speech: noun, adjective

Definitions

1. Something that causes drowsiness or induces a deep sleep, such as a sedative drug or a dull, tedious activity
2. A substance or thing that brings on sleepiness, often a medicine or a monotonous experience that lulls one to rest
3. Anything that makes a person sleepy, whether a drug taken for insomnia or a lengthy, boring speech that sends listeners off

Etymology: Soporifer is a Latin-derived word built from "sopor," meaning deep sleep, and "-fer," from "ferre," to bear or carry. Literally, it means "sleep-bearing" or "sleep-bringing." English took it in the sense of something that induces sleep, and it is used both as an adjective and as a noun for a drug or substance that does so. The word is a close relative of "soporific," which has the same root and the same meaning. Both were formed from Latin materials, and the "-fer" ending shows up in many English words borrowed from Latin, such as "ferry" and "fertile," which share the same root meaning "to bear."