The Spanish word 'soltería' (meaning 'the state of being single') comes from combining the Spanish word 'soltero' (meaning 'single' or 'unmarried') with the suffix '-ía' (which indicates a state or condition). The word 'soltero' itself can be traced back to the Latin word 'solitarius' meaning 'solitary' or 'alone', which in turn derives from the Latin 'solus' meaning 'alone'.

This etymology shows how the concept of being unmarried or single became associated with the idea of being alone or solitary, and how adding the suffix '-ía' transformed the adjective into a noun describing the state itself.

Some related Spanish words that might be more familiar to Spanish learners include 'soltero/soltera' (single person), and 'solo' (alone). These all share the common Latin root 'solus' meaning 'alone'. While 'solo' directly refers to being alone or by oneself, 'soltero' and 'soltería' specifically evolved to refer to being unmarried or the state of being unmarried.

English speakers might recognize the connection to words like 'solitary', 'solo', and 'sole', which all come from the same Latin root 'solus'. While these English words maintained meanings closer to the original sense of being alone or unique, the Spanish 'soltería' developed the more specific meaning of being unmarried. The English word 'solitary' is particularly close to the Latin 'solitarius' that gave rise to Spanish 'soltero'.