The Spanish word "hielo" meaning "ice" comes from the Latin word "gelum" which meant "frost, ice". The evolution from Latin "gelum" to Spanish "hielo" showcases some typical sound changes that occurred as Latin developed into Spanish. The initial 'g' sound softened and became an 'h' sound (which is now silent in modern Spanish), and the 'e' diphthongized into 'ie', a common phonetic change in Spanish evolution from Latin.

Some related Spanish words include "helar" (to freeze), "helado" (ice cream or frozen), and "helada" (frost). All these words share the same Latin root and maintain related meanings around the concept of freezing or ice.

English speakers might recognize this etymology in words like "gel" and "gelatin", which come from the same Latin root "gelum". While these English words have evolved to refer more to jelly-like substances rather than ice specifically, they retain a connection to the original meaning through the concept of something becoming firm or solid. The word "congeal" is another related term that more directly reflects the freezing or solidifying aspect of the original Latin meaning.