slug

Where does the word "slug" come from? It comes from Old Norse sluggi, and was adopted directly into English (1300s).

Slug’s story begins in Old Norse: sluggi meant “a slow, lazy person.” The garden slug took the name from the idea of slowness in the 1700s. It reached English by 1300s as slug. Broadened from a lazy person to the slow-moving, shell-less mollusk. Today, slug means a slow-moving, shell-less land mollusk.

1. Stage 1 · Old Norse · medieval sluggi "a slow, lazy person", the garden slug took the name from the idea of slowness in the 1700s.
2. Stage 2 · English · 1300s slug "a slow-moving, shell-less mollusk, or a lazy person", broadened from a lazy person to the slow-moving, shell-less mollusk.