means The seasonal or long-term movement of people, animals, or things from one place to another, usually in search of better conditions.

from From Latin 'migrare,' to move from one place to another, which gave us 'migratio' — a relocation. It's a cousin of 'mutare,' to change, sharing the deep Indo-European sense of shifting position. English borrowed it in the 1600s, first for the wholesale movements of peoples, and the birds and butterflies joined the word's territory soon after.