The Spanish word 'trigonométrico' (trigonometric) comes from combining two Ancient Greek elements with a Spanish suffix. The first part comes from Greek 'trigonon' meaning 'triangle', and the second from Greek 'metron' meaning 'measure'. These combined to form 'trigonometria' (trigonometry), literally meaning 'triangle measurement'. The adjective form was then created by adding the Spanish suffix '-ico', which forms adjectives from nouns, giving us 'trigonométrico'.

This etymology reflects the mathematical nature of trigonometry as the study and measurement of triangles and their properties.

Some related and simpler Spanish words include 'métrico' (metric), which shares the same Greek root 'metron' for measurement, and 'triángulo' (triangle), which while not directly from 'trigonon', expresses the same concept of a three-angled shape.

English speakers can recognize the connection to familiar words like 'trigonometry' and 'metric', which share the same Greek origins. The word 'meter' (as in both the measurement unit and a device for measuring) also comes from the Greek 'metron'. The 'tri-' prefix seen in words like 'triangle', 'tripod', and 'trilogy' shares the concept of 'three' that's present in 'trigonométrico'.