The Spanish word 'vizconde' (meaning 'viscount') comes from the Medieval Latin 'vicecomes', which was formed by combining two Latin words: 'vicem' meaning 'in place of' and 'comes' meaning 'companion'. This literally meant someone who acted in place of or as a deputy to a count (comes). The Latin term evolved into Spanish through regular sound changes, with 'vice-' becoming 'viz-' and 'comes' simplifying to 'conde'.

This title originated in the feudal system, where a viscount would serve as the deputy or lieutenant of a count, managing the count's affairs when they were absent.

A simpler related Spanish word is 'conde' (meaning 'count'), which comes directly from the Latin 'comes'. You can think of 'vizconde' as 'viz-' (meaning 'vice' or 'deputy') + 'conde', literally a 'vice-count'. Another related word is 'condado' meaning 'county' or 'countship'.

The English word 'viscount' is a direct parallel to 'vizconde', coming from the same Latin source 'vicecomes'. The English word 'count' (as a title of nobility) is also related, coming from 'comes'. Additionally, the English prefix 'vice-' as in 'vice-president' or 'vice-chairman' comes from the same Latin 'vicem' that gives us the 'viz-' in 'vizconde'.