The Spanish verb 'guisar' (to cook, prepare) has an interesting Germanic origin. It comes from the Spanish noun 'guisa' meaning 'manner or way', which itself derives from Proto-Germanic 'wīsō' (also meaning 'manner, way'). The verb was formed by adding the Spanish infinitive suffix '-ar' to 'guisa'. The semantic evolution from 'manner, way' to 'to cook, prepare' likely developed from the idea of preparing something in a particular manner or way.

A simpler related Spanish word is 'guisa', meaning 'manner' or 'way'. While this word is less common in modern Spanish, you might see it in phrases like 'a la guisa de' (in the manner of). The connection between 'guisa' and 'guisar' shows how the basic meaning of 'manner/way' evolved into the more specific meaning of preparing or cooking food in a particular way.

English speakers might recognize a connection to words like 'wise' and 'way', which share the same Proto-Germanic root 'wīsō'. Just as 'wise' relates to knowing the proper manner or way of doing things, 'guisar' developed to specifically mean knowing the proper way to prepare food. The English word 'guise' (meaning appearance or manner) is also related, having come through French from the same Germanic root.