noun
spout cup; feeding cup
A small cup with a spout, traditionally used for giving liquids to someone who is ill or bedridden. Also called a convalescent feeding cup.
祖母が寝ているときは、吸い飲みでお茶を飲ませた。
When my grandmother was bedridden, we gave her tea using a spout cup.
病院では、口が不自由な患者に吸い飲みを使うことがある。
In hospitals, they sometimes use a feeding cup for patients who have difficulty drinking.
Compound of 吸い (sui, 'sucking', from 吸う) and 飲み (nomi, 'drinking', from 飲む). The spelling 呑み is a variant using the character for 'drink' or 'swallow'.