The Spanish word 'fija' (feminine form of 'fijo', meaning 'fixed') comes from the Latin word 'fixus', meaning 'fixed' or 'fastened', which in turn derives from the Latin verb 'figere', meaning 'to fix' or 'to fasten'. The feminine form is created by adding the Spanish feminine suffix '-a' to the masculine form 'fijo'.

This etymology shows a clear path from the Latin action of fastening or fixing something in place, to the modern Spanish adjective describing something that is fixed or stationary.

Some common related Spanish words include 'fijo' (fixed, permanent), 'fijar' (to fix, to fasten), and 'fijación' (fixation, attachment). All these words share the core meaning of something being fixed or attached in place.

English speakers can easily remember 'fija' by connecting it to several similar English words that share the same Latin root, such as 'fix', 'fixed', 'fixture', and 'affix'. All these words maintain the basic concept of fastening or securing something in place. The connection between Spanish 'fija' and English 'fix' makes this word particularly easy to remember for English speakers.