kulero

No suffix in sight, however much it looks like one. Kulero ends in -ero, and -er- is a real and busy Esperanto suffix meaning one small piece of a mass: sablo sand gives sablero a grain of sand, neĝo snow gives neĝero a snowflake, mono money gives monero a coin. So the eye offers you kul- plus -er-, a small piece of a kulo. A kulo is a mosquito. A spoon is not a piece of a mosquito, and kuler- is one indivisible borrowed root.

The measure word. Kulero names the object; a spoonful is kulerplena or, far more often, the plain du kuleroj da sukero with da doing the work. Kulereto is a teaspoon and supkulero a soup spoon or tablespoon. Kuleri means to spoon something out. The table set is worth learning as a group: telero a plate, forko a fork, tranĉilo a knife (transparently a cutting-tool), taso a cup and glaso a glass.

The snail is real. Latin cochlea meant a snail or anything spiral, and cochlear was the implement for eating one: a small bowl with a spike on the other end. The bowl outlived the spike, the word outlived the Romans, and the same cochlea is still sitting in your inner ear, where the spiral cavity is called the cochlea because it looks like a snail shell. Ask for a spoon in Esperanto and you are, at four removes, asking for a snail.