レタス (retasu) means “lettuce” | MotiTan Japanese Dictionary

More examples

お昼にレタスを食べます。o hiru ni re ta su o ta be ma su

I eat lettuce for lunch.

レタスを手でちぎって、サンドイッチに挟みます。re ta su o te de chi gi tte sa n do i tchi ni hasa mi ma su

I tear the lettuce by hand and put it in a sandwich.

Refers to a leafy vegetable with a mild taste and crisp texture that is often eaten raw.

ちしゃchisha: A traditional Japanese name for the leafy vegetable commonly used in salads.

サラダなどに用いる、薄く柔らかな葉を食用とする野菜。sa ra da na do ni mochi i ru usu ku yawa ra ka na ha o shoku yō to su ru ya sai

The Japanese noun レタス (retasu) is borrowed from English lettuce, which traces through French laitue to Latin lactuca.

In English, lettuce is usually treated as an uncountable food name, while one whole plant is commonly called a head of lettuce.