The Spanish word 'suéter' comes directly from the English word 'sweater'. The English term was formed by combining the verb 'sweat' with the agent suffix '-er', literally meaning 'something that makes one sweat'. This name originated because early sweaters were thick garments worn during athletic activities that would cause the wearer to perspire.

There aren't any simpler or more common Spanish words that are etymologically related to 'suéter', as it is a direct borrowing from English.

The Spanish 'suéter' is directly related to the English word 'sweater'. You can easily see how the Spanish spelling adapts the English pronunciation: the 'sw' becomes 'su', and an accent is added to maintain the correct stress pattern in Spanish. The word is also related to the English verb 'to sweat', which helps explain why this garment got its name - early sweaters were thick wool garments worn during exercise or athletic activities.