The Spanish word 'obeso' (meaning 'obese') comes from the Latin word 'obesus', which meant 'having eaten excessively' or 'fat'. The Latin 'obesus' was formed by combining two elements: the prefix 'ob-' meaning 'against' or 'facing', and 'esus', which was the past participle of the Latin verb 'edere' meaning 'to eat'. So literally, the word developed from the concept of someone who had 'eaten against' or 'eaten in front of' themselves, painting a vivid picture of excessive eating.

While 'obeso' itself is a relatively common Spanish word, you might encounter the related word 'comedor' (eater) which, although from a different Latin root ('comedere'), carries a similar connection to eating. The Spanish verb 'comer' (to eat) is more commonly used than any derivatives of the Latin 'edere' in modern Spanish.

The English word 'obese' is a direct cognate of Spanish 'obeso', as both come from the same Latin root 'obesus'. This makes it very easy for English speakers to remember the Spanish word. Another related English word is 'edible' (meaning 'able to be eaten'), which comes from the same Latin verb 'edere' (to eat) that formed part of the origin of 'obeso'.